A multipass laser amplifier includes a mirror, a mirror device, a gain crystal, and refractive or diffractive beam-steering element. The gain crystal is positioned on a longitudinal axis of the multipass laser amplifier between the mirror and the mirror device. The beam-steering element is positioned on the longitudinal axis between the gain crystal and the mirror device. The beam-steering element has no optical power and deflects a laser beam, by refraction or diffraction, for each of multiple passes of the laser beam between the first mirror and the mirror device, such that each pass goes through the gain crystal for amplification of the laser beam and goes through a different respective off-axis portion of the beam-steering element. The no optical power of the beam-steering element enables maintaining a large beam size in the gain crystal, thereby facilitating amplification to high average power.
A method for frequency conversion in a single-longitudinal-mode linear resonator includes frequency converting intracavity laser radiation in a nonlinear crystal disposed in a linear resonator. The intracavity laser radiation is in a single longitudinal mode of the resonator and forms a standing wave between its end-mirrors. The method also includes repeatedly sweeping the standing wave back and forth, along an optical axis of the resonator, relative to the nonlinear crystal. This repeated sweeping may be achieved by dithering the longitudinal position of (a) one or both of the end-mirrors or (b) the nonlinear crystal. Dithering of a single end-mirror may be driven by modulating a reference wavelength to which the wavelength of the intracavity laser radiation is locked. Dithering of the longitudinal position of the nonlinear crystal may be achieved with a piezoelectric actuator arranged to adjust angles of a parallelogram-shaped flexure to which the nonlinear crystal is mounted.
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
H01S 3/105 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation par commande de la position relative ou des propriétés réfléchissantes des réflecteurs de la cavité
H01S 3/109 - Multiplication de la fréquence, p. ex. génération d'harmoniques
H01S 3/131 - Stabilisation de paramètres de sortie de laser, p. ex. fréquence ou amplitude par commande du milieu actif, p. ex. par commande des procédés ou des appareils pour l'excitation
A method for laser cutting metal foils includes generating a linearly polarized CW laser beam (190) with a fiber laser system (110), modulating diffraction of the continuous-wave laser beam (190) by an acousto-optic modulator (120) to produce a pulsed laser beam (194), and cutting a metal foil (180) with the pulsed laser beam (194). The present method can modulate a high-power CW laser beam (190) on and off at a high modulation rate, e.g., 100 kilohertz or more, to generate a pulsed laser beam (194). The power of the CW laser beam (190) may be between 0.5 and several kilowatts. Modulation may be done with a duty cycle of approximately 50%. This method is thus capable of providing high average-power while operating with sufficiently short pulses and sufficiently long time between pulses to keep the heat- affected zone small.
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
B23K 26/38 - Enlèvement de matière par perçage ou découpage
B23K 26/073 - Détermination de la configuration du spot laser
A terminated hollow-core optical fiber includes a capillary, a hollow-core optical fiber including a structured cladding, and an endcap. A first end of the hollow-core optical fiber terminates inside the capillary a non-zero distance away from a first end face of the capillary. The hollow-core optical fiber is adhered to the capillary at a second end face of the capillary where the hollow-core optical fiber extends out of the capillary. The endcap is fused to the first end face of the capillary. The endcap has a larger diameter than the first end of the hollow-core optical fiber. This termination scheme does not require fusing the hollow-core fiber itself to the endcap or any other part. Therefore, this termination scheme is applicable to hollow-core fibers with a structured cladding that cannot tolerate the temperatures associated with fusing the hollow-core fiber to another part.
A composite filter (100) includes a substrate (110) and, disposed thereon, a dielectric reststrahlen coating (120) and a dielectric coating stack (130). The substrate (110) is transmissive in a first infrared wavelength range from 9 to 11 micrometers as well as in neighboring infrared wavelength ranges above and below the first infrared wavelength range. The dielectric reststrahlen coating (120) has a reststrahlen band that overlaps with the first infrared wavelength range and contains at least one carbon dioxide laser wavelength, and is partly absorptive at the carbon dioxide wavelength(s). The dielectric coating stack (130) forms a multilayer interference filter that is predominantly reflective at the carbon dioxide laser wavelength(s) and predominantly transmissive in a second infrared wavelength range below the reststrahlen band.
A fiber-optic cable (100) includes an optical fiber (110) that transports a forward- propagating laser beam. The optical fiber includes a core (112), a cladding (114), and an output end-face (116) emitting the forward-propagating beam (190). The fiber-optic cable (100) also includes a mode-stripper (120), along a segment of the optical fiber (110), that couples out backward-propagating radiation (194) that has been coupled into the cladding (114) at the output end-face (116). The fiber-optic cable (100) further includes a waveguide (130) having a waveguide body (132) with a bore (134) containing at least part of the segment of the optical fiber (110). The bore (132) is defined by an inward-facing surface (138) that guides at least a fraction of the backward-propagating radiation (194), coupled out of the cladding (114) by the mode-stripper (120), toward a rear opening of the bore (134) farthest from the output end-face (116). Additionally, the fiber-optic cable (100) includes one or more sensors (150) or fiber ports that receive portions of the backward-propagating radiation (194) emerging from the rear opening.
A fiber-optic cable includes an optical fiber that transports a forward-propagating laser beam. The optical fiber includes a core, a cladding, and an output end-face emitting the forward-propagating beam. The fiber-optic cable also includes a mode-stripper, along a segment of the optical fiber, that couples out backward-propagating radiation that has been coupled into the cladding at the output end-face. The fiber-optic cable further includes a waveguide having a waveguide body with a bore containing at least part of the segment of the optical fiber. The bore is defined by an inward-facing surface that guides at least a fraction of the backward-propagating radiation, coupled out of the cladding by the mode-stripper, toward a rear opening of the bore farthest from the output end-face. Additionally, the fiber-optic cable includes one or more sensors or fiber ports that receive portions of the backward-propagating radiation emerging from the rear opening.
The invention concerns an apparatus and its use for laser welding. A laser welding apparatus comprise at least one first laser device, each providing at least one first optical feed fiber with a first laser beam; at least one second laser device, each providing at least one second optical feed fiber with a second laser beam; means for generating a composite laser beam comprising a first output laser beam and a second output laser beam for welding a workpiece; wherein the first output laser beam has a circular cross-section and the second output laser beam has an annular shape concentric to the first output laser beam. The second laser device is a fiber laser device or a fiber-coupled laser device. The apparatus is configured to form the second output laser beam at least on the basis of the second laser beam, and the second output laser beam comprises a first wavelength and a second wavelength having difference of at least 10 nanometers, or the second output laser beam has spectrum width of least 10 nanometers.
A laser frequency conversion system with ultraviolet-damage mitigation includes a nonlinear crystal for frequency converting a laser beam, and a one-dimensional beam expander arranged to receive the laser beam from the nonlinear crystal and expand a first transverse dimension of the laser beam. This expansion protects subsequent optical elements from ultraviolet damage. To mitigate ultraviolet damage to the nonlinear crystal and the beam expander, the system also includes one or more translation stages configured to translate the nonlinear crystal and the beam expander along a translation direction that is orthogonal to the first transverse dimension of the laser beam and non-parallel to a propagation direction of the laser beam through the nonlinear crystal and the beam expander.
A terminated hollow-core optical fiber (100) includes a capillary (120), a hollow-core optical fiber (110) including a structured cladding, and an endcap (130). A first end of the hollow-core optical fiber (110) terminates inside the capillary (120) a non-zero distance away from a first end face (122) of the capillary (120). The hollow-core optical fiber (110) is adhered to the capillary (120) at a second end face (124) of the capillary (120) where the hollow-core optical fiber (110) extends out of the capillary (120). The endcap (130) is fused to the first end face (122) of the capillary (120). The endcap (130) has a larger diameter than the first end of the hollow-core optical fiber (110). This termination scheme does not require fusing the hollow-core fiber itself to the endcap (130) or any other part. Therefore, this termination scheme is applicable to hollow-core fibers with a structured cladding that cannot tolerate the temperatures associated with fusing the hollow-core fiber to another part.
A terminated hollow-core optical fiber includes a capillary, a hollow-core optical fiber including a structured cladding, and an endcap. A first end of the hollow-core optical fiber terminates inside the capillary a non-zero distance away from a first end face of the capillary. The hollow-core optical fiber is adhered to the capillary at a second end face of the capillary where the hollow-core optical fiber extends out of the capillary. The endcap is fused to the first end face of the capillary. The endcap has a larger diameter than the first end of the hollow-core optical fiber. This termination scheme does not require fusing the hollow-core fiber itself to the endcap or any other part. Therefore, this termination scheme is applicable to hollow-core fibers with a structured cladding that cannot tolerate the temperatures associated with fusing the hollow-core fiber to another part.
A Q-switched gas laser apparatus with bivariate pulse equalization includes a gas laser, a sensor, and an electronic circuit. A Q-switch that switches the laser resonator between high-loss and low-loss states to generate a pulsed laser beam. The sensor obtains a measurement of the pulsed laser beam indicative of the laser pulse energy. The electronic circuitry operates the Q-switch to (a) repeatedly switch the laser resonator between the high-loss and low-loss states to set a repetition rate of laser pulses of the pulsed laser beam, (b) adjust a loss level of the low-loss state, based on the pulse energy measurement, to achieve a target laser pulse energy, and (c) adjust a duration of the low-loss state to achieve a target laser pulse duration. By adjusting both pulse energy and duration, uniform pulse energy and, if desired, uniform pulse duration are achieved over a wide range of repetition rates.
H01S 3/223 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet caractérisés par le matériau utilisé comme milieu actif à gaz le gaz actif étant polyatomique, c.-à-d. contenant plusieurs atomes
H01S 3/117 - Commutation-Q utilisant des dispositifs acousto-optiques dans la cavité
H01S 3/13 - Stabilisation de paramètres de sortie de laser, p. ex. fréquence ou amplitude
H01S 3/136 - Stabilisation de paramètres de sortie de laser, p. ex. fréquence ou amplitude par commande de dispositifs placés dans la cavité
H01S 3/10 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation
H01S 3/106 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation par commande de dispositifs placés dans la cavité
H01S 3/23 - Agencement de plusieurs lasers non prévu dans les groupes , p. ex. agencement en série de deux milieux actifs séparés
A Q-switched gas laser apparatus with bivariate pulse equalization includes a gas laser, a sensor, and an electronic circuit. A Q-switch that switches the laser resonator between high-loss and low-loss states to generate a pulsed laser beam. The sensor obtains a measurement of the pulsed laser beam indicative of the laser pulse energy. The electronic circuitry operates the Q-switch to (a) repeatedly switch the laser resonator between the high-loss and low-loss states to set a repetition rate of laser pulses of the pulsed laser beam, (b) adjust a loss level of the low-loss state, based on the pulse energy measurement, to achieve a target laser pulse energy, and (c) adjust a duration of the low-loss state to achieve a target laser pulse duration. By adjusting both pulse energy and duration, uniform pulse energy and, if desired, uniform pulse duration are achieved over a wide range of repetition rates.
H01S 3/136 - Stabilisation de paramètres de sortie de laser, p. ex. fréquence ou amplitude par commande de dispositifs placés dans la cavité
H01S 3/117 - Commutation-Q utilisant des dispositifs acousto-optiques dans la cavité
H01S 3/13 - Stabilisation de paramètres de sortie de laser, p. ex. fréquence ou amplitude
H01S 3/223 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet caractérisés par le matériau utilisé comme milieu actif à gaz le gaz actif étant polyatomique, c.-à-d. contenant plusieurs atomes
15.
ACTIVELY COOLED END-PUMPED SOLID-STATE LASER GAIN MEDIUM
An actively cooled end-pumped solid-state laser gain device includes a bulk solid-state gain medium. An input-end of the gain medium receives a pump laser beam incident thereon and propagating in the direction toward an opposite output-end. The metal foil is disposed over a face of the gain medium extending between the input- and output-ends. A housing cooperates with the metal foil to form a coolant channel on the face the gain medium. The coolant channel has an inlet and an outlet configured to conduct a flow of coolant along the metal foil from the input-end towards the output-end. The metal foil is secured between the gain medium and portions of the housing running adjacent to the coolant channel. The metal foil provides a reliable thermal contact and imparts little or no stress on the bulk gain medium.
H01S 3/042 - Dispositions pour la gestion thermique pour des lasers à l'état solide
H01S 3/0941 - Procédés ou appareils pour l'excitation, p. ex. pompage utilisant le pompage optique par de la lumière cohérente produite par un laser à semi-conducteur, p. ex. par une diode laser
H01S 3/04 - Dispositions pour la gestion thermique
H05K 7/20 - Modifications en vue de faciliter la réfrigération, l'aération ou le chauffage
16.
ACTIVELY COOLED END-PUMPED SOLID-STATE LASER GAIN MEDIUM
An actively cooled end-pumped solid-state laser gain device includes a bulk solid-state gain medium. An input-end of the gain medium receives a pump laser beam incident thereon and propagating in the direction toward an opposite output-end. The metal foil is disposed over a face of the gain medium extending between the input- and output-ends. A housing cooperates with the metal foil to form a coolant channel on the face the gain medium. The coolant channel has an inlet and an outlet configured to conduct a flow of coolant along the metal foil from the input-end towards the output-end. The metal foil is secured between the gain medium and portions of the housing running adjacent to the coolant channel. The metal foil provides a reliable thermal contact and imparts little or no stress on the bulk gain medium.
H01S 3/0941 - Procédés ou appareils pour l'excitation, p. ex. pompage utilisant le pompage optique par de la lumière cohérente produite par un laser à semi-conducteur, p. ex. par une diode laser
Laser welding methods include focusing laser radiation onto a first metal sheet disposed on a metal part, optionally with one or more intervening metal sheets therebetween. The laser radiation is steered to trace at least one spiral path to spot-weld together the metal parts. The laser radiation includes a center beam and an annular beam to maintain a stable keyhole. One method is tailored to weld aluminum parts, e.g., with high gas content and/or dissimilar compositions, and the laser radiation traces first an outward spiral path and then an inward spiral path. The center beam is pulsed during one segment of the inward spiral path. Another method is tailored to weld steel or copper parts having a coating at an interface therebetween, and the laser radiation traces an inward spiral path. The interface may be a zero-gap interface, or a non-zero gap may exist.
B23K 26/28 - Soudage de joints continus curvilignes
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/073 - Détermination de la configuration du spot laser
A thermally actuated adaptive optic includes a base, a reflector, and a plurality of actuators coupled therebetween. The reflector has a light-receiving front surface, and a back surface facing the base. Each actuator includes a bracket rigidly bonded to the reflector at a perimeter of the reflector, and an inner rod and. an outer rod. Each rod is rigidly connected between the bracket and the base, with the inner rod being closer to a center of the reflector. The length of each rod is temperature dependent. In another adaptive optic, the rods are instead bonded directly to the reflector. This adaptive optic may be modified to implement an integrally formed, thermally actuated support. The disclosed adaptive optics are suitable for use in laser systems, allow for significant cost savings over piezoelectric devices, provide a reflective area free of surface-figure perturbations caused by the actuator- interfaces, and are relatively simple to manufacture.
G02B 26/08 - Dispositifs ou dispositions optiques pour la commande de la lumière utilisant des éléments optiques mobiles ou déformables pour commander la direction de la lumière
A thermally actuated adaptive optic includes a base, a reflector, and a plurality of actuators coupled therebetween. The reflector has a light-receiving front surface, and a back surface facing the base. Each actuator includes a bracket rigidly bonded to the reflector at a perimeter of the reflector, and an inner rod and an outer rod. Each rod is rigidly connected between the bracket and the base, with the inner rod being closer to a center of the reflector. The length of each rod is temperature dependent. In another adaptive optic, the rods are instead bonded directly to the reflector. This adaptive optic may be modified to implement an integrally formed, thermally actuated support. The disclosed adaptive optics are suitable for use in laser systems, allow for significant cost savings over piezoelectric devices, provide a reflective area free of surface-figure perturbations caused by the actuator-interfaces, and are relatively simple to manufacture.
G02B 7/182 - Montures, moyens de réglage ou raccords étanches à la lumière pour éléments optiques pour prismesMontures, moyens de réglage ou raccords étanches à la lumière pour éléments optiques pour miroirs pour miroirs
G02B 7/18 - Montures, moyens de réglage ou raccords étanches à la lumière pour éléments optiques pour prismesMontures, moyens de réglage ou raccords étanches à la lumière pour éléments optiques pour miroirs
Laser welding methods include focusing laser radiation (120) onto a first metal sheet (112) disposed on a metal part (114), optionally with one or more intervening metal sheets therebetween. The laser radiation (120) is steered to trace at least one spiral path to spot-weld together the metal parts (114). The laser radiation (120) includes a center beam (122C) and an annular beam (122A) to maintain a stable keyhole. One method is tailored to weld aluminum parts, e.g., with high gas content and/or dissimilar compositions, and the laser radiation (120) traces first an outward spiral path (810) and then an inward spiral path (830). The center beam (122C) is pulsed during one segment of the inward spiral path (830). Another method is tailored to weld steel or copper parts having a coating at an interface therebetween, and the laser radiation (120) traces an inward spiral path (830). The interface (414F) may be a zero- gap interface, or a non-zero gap may exist.
Laser welding methods include focusing laser radiation (120) onto a first metal sheet (112) disposed on a metal part (114), optionally with one or more intervening metal sheets therebetween. The laser radiation (120) is steered to trace at least one spiral path to spot-weld together the metal parts (114). The laser radiation (120) includes a center beam (122C) and an annular beam (122A) to maintain a stable keyhole. One method is tailored to weld aluminum parts, e.g., with high gas content and/or dissimilar compositions, and the laser radiation (120) traces first an outward spiral path (810) and then an inward spiral path (830). The center beam (122C) is pulsed during one segment of the inward spiral path (830). Another method is tailored to weld steel or copper parts having a coating at an interface therebetween, and the laser radiation (120) traces an inward spiral path (830). The interface (414F) may be a zero- gap interface, or a non-zero gap may exist.
A system (100) for nonlinear frequency conversion includes an acousto- optic modulator (110) for diffracting a portion of an input laser beam (190) as a first-order beam (192(1)) and transmitting a non-diffracted portion of the input laser (190) beam as a zeroth-order beam (192(0)). The system (100) also includes a nonlinear crystal (120) arranged to receive and frequency convert each of the zeroth-order (192(0)) and first-order (192(1)) beams to generate two respective frequency-converted laser beams (198(0),198(1)), whereby, when the acousto-optic modulator (110) changes the average-power ratio between the zeroth-order (192(0)) and first-order (192(1)) beams, variations of the heat load in the nonlinear crystal (120) are minimized. Either one of the two frequency-converted laser beams (198(0),198(1)) may be used as an output laser beam of the system (100), while the other one of the two frequency-converted laser beams (198(0),198(1)) serves to stabilize the heat load in the nonlinear crystal (120) when the acousto-optic modulator (110) is operated to change the average power in the output laser beam.
G02F 1/11 - Dispositifs ou dispositions pour la commande de l'intensité, de la couleur, de la phase, de la polarisation ou de la direction de la lumière arrivant d'une source lumineuse indépendante, p. ex. commutation, ouverture de porte ou modulationOptique non linéaire pour la commande de l'intensité, de la phase, de la polarisation ou de la couleur basés sur des éléments acousto-optiques, p. ex. en utilisant la diffraction variable par des ondes sonores ou des vibrations mécaniques analogues
Laser welding methods include focusing laser radiation onto a first metal sheet disposed on a metal part, optionally with one or more intervening metal sheets therebetween. The laser radiation is steered to trace at least one spiral path to spot-weld together the metal parts. The laser radiation includes a center beam and an annular beam to maintain a stable keyhole. One method is tailored to weld aluminum parts, e.g., with high gas content and/or dissimilar compositions, and the laser radiation traces first an outward spiral path and then an inward spiral path. The center beam is pulsed during one segment of the inward spiral path. Another method is tailored to weld steel or copper parts having a coating at an interface therebetween, and the laser radiation traces an inward spiral path. The interface may be a zero-gap interface, or a non-zero gap may exist.
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
An optomechanical assembly (100) for temperature-robust laser beam processing includes a baseplate (110) and an optics plate (130). The baseplate includes a source area (112) for accommodating a source (160) of the laser beam, and a light-processing area (114) located away from the source area and including first (116) and second anchor points (118). The optics plate is disposed in the light¬ processing area and includes first (132) and second portions (134) and a flexible coupling (136) interconnecting the first and second portions. The first and second portions are fixed to the baseplate at the first and second anchor points, respectively. The flexible coupling allows for a thermally-induced change in distance between the first and second anchor points in the presence of dissimilar thermal expansion of the optics plate and the baseplate. The assembly further includes a linearly arranged series of optical elements (142) for manipulating a laser beam from the laser source. Each of the optical elements is rigidly bonded to the first portion (132). The coefficient of thermal expansion (CTE) of the optics plate (130) is matched to the CTEs of the optical elements (142).
An optomechanical assembly for temperature-robust laser beam processing includes a baseplate and an optics plate. The baseplate includes a source area for accommodating a source of the laser beam, and a light-processing area located away from the source area and including first and second anchor points. The optics plate is disposed in the light-processing area and includes first and second portions and a flexible coupling interconnecting the first and second portions. The first and second portions are fixed to the baseplate at the first and second anchor points, respectively. The flexible coupling allows for a thermally-induced change in distance between the first and second anchor points in the presence of dissimilar thermal expansion of the optics plate and the baseplate. The assembly further includes a series of optical elements for manipulating a laser beam from the laser source. Each of the optical elements is rigidly bonded to the first portion.
B23K 26/064 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples au moyen d'éléments optiques, p. ex. lentilles, miroirs ou prismes
G02B 7/02 - Montures, moyens de réglage ou raccords étanches à la lumière pour éléments optiques pour lentilles
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
An ultrashort-pulse compressor includes (a) one or more bulk-optics intersecting a propagation path of an ultrashort-pulsed laser beam multiple times to spectrally broaden a pulse of the laser beam during each of multiple passes through the bulk-optic(s), (b) one or more dispersive optics for compressing a duration of the pulse after each of the multiple passes, and (c) a plurality of focusing elements for focusing the laser beam between the multiple passes. Propagation distances between the bulk-optic(s) and the focusing elements are detuned from imaging such that a spot size of the laser beam, at the bulk-optic(s), is greater at each successive one of the multiple passes. As the laser beam propagates through this compressor, each laser pulse is alternatingly spectral broadened and temporally compressed. The increasing spot size of the laser, for each pass, helps prevent optical damage, run- away self-focusing, and other undesirable outcomes.
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
An ultrashort-pulse compressor includes (a) one or more bulk-optics intersecting a propagation path of an ultrashort-pulsed laser beam multiple times to spectrally broaden a pulse of the laser beam during each of multiple passes through the bulk-optic(s), (b) one or more dispersive optics for compressing a duration of the pulse after each of the multiple passes, and (c) a plurality of focusing elements for focusing the laser beam between the multiple passes. Propagation distances between the bulk-optic(s) and the focusing elements are detuned from imaging such that a spot size of the laser beam, at the bulk-optic(s), is greater at each successive one of the multiple passes. As the laser beam propagates through this compressor, each laser pulse is alternatingly spectral broadened and temporally compressed. The increasing spot size of the laser, for each pass, helps prevent optical damage, run-away self-focusing, and other undesirable outcomes.
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/046 - Focalisation automatique du faisceau laser
28.
Nonlinear frequency conversion with variable average power and stable heat load
A system for nonlinear frequency conversion includes an acousto-optic modulator for diffracting a portion of an input laser beam as a first-order beam and transmitting a non-diffracted portion of the input laser beam as a zeroth-order beam. The system also includes a nonlinear crystal arranged to receive and frequency convert each of the zeroth-order and first-order beams to generate two respective frequency-converted laser beams, whereby, when the acousto-optic modulator changes the average-power ratio between the zeroth-order and first-order beams, variations of the heat load in the nonlinear crystal are minimized. Either one of the two frequency-converted laser beams may be used as an output laser beam of the system, while the other one of the two frequency-converted laser beams serves to stabilize the heat load in the nonlinear crystal when the acousto-optic modulator is operated to change the average power in the output laser beam.
G02F 1/37 - Optique non linéaire pour la génération de l'harmonique deux
G02F 1/11 - Dispositifs ou dispositions pour la commande de l'intensité, de la couleur, de la phase, de la polarisation ou de la direction de la lumière arrivant d'une source lumineuse indépendante, p. ex. commutation, ouverture de porte ou modulationOptique non linéaire pour la commande de l'intensité, de la phase, de la polarisation ou de la couleur basés sur des éléments acousto-optiques, p. ex. en utilisant la diffraction variable par des ondes sonores ou des vibrations mécaniques analogues
A multipass laser amplifier (100) includes a mirror (130), a mirror device (140), a gain crystal (120), and refractive or diffractive beam-steering element (110). The gain crystal (120) is positioned on a longitudinal axis of the multipass laser amplifier (100) between the mirror (130) and the mirror device (140). The beam-steering element (110) is positioned on the longitudinal axis between the gain crystal (120) and the mirror device (140). The beam-steering element (110) has no optical power and deflects a laser beam, by refraction or diffraction, for each of multiple passes of the laser beam between the first mirror (130) and the mirror device (140), such that each pass goes through the gain crystal (120) for amplification of the laser beam and goes through a different respective off-axis portion of the beam-steering element (110). The no optical power of the beam-steering element (110) enables maintaining a large beam size in the gain crystal (120), thereby facilitating amplification to high average power.
H01S 3/23 - Agencement de plusieurs lasers non prévu dans les groupes , p. ex. agencement en série de deux milieux actifs séparés
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
H01S 3/08 - Structure ou forme des résonateurs optiques ou de leurs composants
H01S 3/094 - Procédés ou appareils pour l'excitation, p. ex. pompage utilisant le pompage optique par de la lumière cohérente
A multipass laser amplifier includes a mirror, a mirror device, a gain crystal, and refractive or diffractive beam-steering element. The gain crystal is positioned on a longitudinal axis of the multipass laser amplifier between the mirror and the mirror device. The beam-steering element is positioned on the longitudinal axis between the gain crystal and the mirror device. The beam-steering element has no optical power and deflects a laser beam, by refraction or diffraction, for each of multiple passes of the laser beam between the first mirror and the mirror device, such that each pass goes through the gain crystal for amplification of the laser beam and goes through a different respective off-axis portion of the beam-steering element. The no optical power of the beam-steering element enables maintaining a large beam size in the gain crystal, thereby facilitating amplification to high average power.
A pulsed third-harmonic laser system includes a pulsed laser, an extra-cavity nonlinear crystal, and an intracavity nonlinear crystal. The pulsed laser generates fundamental laser pulses and couples out a portion of each fundamental laser pulse out of the laser resonator to undergo second-harmonic-generation in the extra-cavity nonlinear crystal. Resulting second-harmonic laser pulses are directed back into the laser resonator and mixes with the fundamental laser pulses in the intracavity nonlinear crystal to generate third-harmonic laser pulses. The pulsed third-harmonic laser system thus maintains a non-zero output coupling efficiency regardless of the efficiency of the second-harmonic-generation stage, while the third-harmonic-generation stage benefits from the intracavity power of the fundamental laser pulses.
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
H01S 3/11 - Blocage de modesCommutation-QAutres techniques d'impulsions géantes, p. ex. vidange de cavité
H01S 3/108 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation par commande de dispositifs placés dans la cavité utilisant des dispositifs optiques non linéaires, p. ex. produisant une diffusion par effet Brillouin ou Raman
33.
PULSED LASER WITH INTRACAVITY FREQUENCY CONVERSION AIDED BY EXTRA-CAVITY FREQUENCY CONVERSION
A pulsed third-harmonic laser system includes a pulsed laser, an extra-cavity nonlinear crystal, and an intracavity nonlinear crystal. The pulsed laser generates fundamental laser pulses and couples out a portion of each fundamental laser pulse out of the laser resonator to undergo second-harmonic-generation in the extra-cavity nonlinear crystal. Resulting second-harmonic laser pulses are directed back into the laser resonator and mixes with the fundamental laser pulses in the intracavity nonlinear crystal to generate third-harmonic laser pulses. The pulsed third-harmonic laser system thus maintains a non-zero output coupling efficiency regardless of the efficiency of the second-harmonic-generation stage, while the third-harmonic-generation stage benefits from the intracavity power of the fundamental laser pulses.
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
H01S 3/109 - Multiplication de la fréquence, p. ex. génération d'harmoniques
H01S 3/108 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation par commande de dispositifs placés dans la cavité utilisant des dispositifs optiques non linéaires, p. ex. produisant une diffusion par effet Brillouin ou Raman
H01S 3/11 - Blocage de modesCommutation-QAutres techniques d'impulsions géantes, p. ex. vidange de cavité
H01S 3/115 - Commutation-Q utilisant des dispositifs électro-optiques dans la cavité
H01S 3/08 - Structure ou forme des résonateurs optiques ou de leurs composants
34.
LASER WELDING OF METAL PIN PAIRS WITH TIME-DEPENDENT SCAN PATTERN AND ENERGY INPUT
A method for laser welding a pair of metal pins delivers a laser beam to a work-side of the pair of metal pins where a respective pair of surfaces of the metal pins are adjacent to each other and face in the same direction. The laser beam first traces a first path on the work-side to form a melt pool by keyhole welding. The first path crosses an interface between the metal pins. After tracing the first path, the laser beam is switched to trace a second path on the work-side with the laser beam at a delivered rate of energy per unit path length that is less than the one used for the first path. The second path crosses the interface and is within the first path. The method is well-suited for welding of hairpin and I-pin stators.
A method for laser welding a pair of metal pins (182,200) delivers a laser beam (112) to a work-side (220) of the pair of metal pins (182,200) where a respective pair of surfaces (204) of the metal pins (182,200) are adjacent to each other and face in the same direction. The laser beam (112) first traces a first path (230,630) on the work-side (220) to form a melt pool (850)by keyhole welding. The first path (230,630) crosses an interface (210) between the metal pins (182,200). After tracing the first path (230,630), the laser beam (112) is switched to trace a second path (240,640) on the work-side (220) with the laser beam (112) at a delivered rate of energy per unit path length that is less than the one used for the first path (230,630). The second path (240,640) crosses the interface (210) and is within the first path (230,630). The method is well-suited for welding of hairpin and I-pin stators.
A method for laser keyhole welding is disclosed to weld two pieces together made of a metal alloy. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power of the annular beam is reduced, motion of the focused beams is stopped, the power of the center beam is increased, and the power of both beams is initially ramped down rapidly and then ramped down slowly. Increasing the power of the center beam equalizes the temperature of both pieces prior to solidification and cooling at the termination of the weld. An additional pulse of power may be applied to prevent the formation of defects or to erase any defects.
B23K 26/244 - Soudage de joints du type à recouvrement
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/073 - Détermination de la configuration du spot laser
A method for laser keyhole welding is disclosed to weld two pieces together made of a metal alloy. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power of the annular beam (PA) is reduced, motion of the focused beams is stopped, the power of the center beam (Pc) is increased, and the power of both beams is initially ramped down rapidly and then ramped down slowly. Increasing the power of the center beam equalizes the temperature of both pieces prior to solidification and cooling at the termination of the weld. An additional pulse of power may be applied to prevent the formation of defects or to erase any defects.
A method for laser keyhole welding is disclosed to weld two pieces together made of a metal alloy. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power of the annular beam (PA) is reduced, motion of the focused beams is stopped, the power of the center beam (Pc) is increased, and the power of both beams is initially ramped down rapidly and then ramped down slowly. Increasing the power of the center beam equalizes the temperature of both pieces prior to solidification and cooling at the termination of the weld. An additional pulse of power may be applied to prevent the formation of defects or to erase any defects.
A method for laser keyhole welding a stack of metal foils (22) to a metal tab (24) is disclosed. The method independently adjusts power in a focused center beam and power in a focused annular beam to form a weld (34) through all the foils (22) and the tab (24). The annular beam provides sufficient power to heat the metal to about melting temperature, widen a mouth of a keyhole, and stabilize a melt pool. The center beam provides sufficient additional power to form the keyhole. The power of the annular beam is sustained for a longer time than the power of the center beam. A plurality of such welds is formed to provide mechanical strength and electrical conductivity.
A method for laser keyhole welding a stack of metal foils to a metal tab is disclosed. The method independently adjusts power in a focused center beam and power in a focused annular beam to form a weld through all the foils and the tab. The annular beam provides sufficient power to heat the metal to about melting temperature, widen a mouth of a keyhole, and stabilize a melt pool. The center beam provides sufficient additional power to form the keyhole. The power of the annular beam is sustained for a longer time than the power of the center beam. A plurality of such welds is formed to provide mechanical strength and electrical conductivity.
A method for laser keyhole welding a stack of metal foils (22) to a metal tab (24) is disclosed. The method independently adjusts power in a focused center beam and power in a focused annular beam to form a weld (34) through all the foils (22) and the tab (24). The annular beam provides sufficient power to heat the metal to about melting temperature, widen a mouth of a keyhole, and stabilize a melt pool. The center beam provides sufficient additional power to form the keyhole. The power of the annular beam is sustained for a longer time than the power of the center beam. A plurality of such welds is formed to provide mechanical strength and electrical conductivity.
22) or carbon monoxide (CO) gas laser includes two electrodes, which have passivated surfaces, within a sealed housing. Features in a ceramic slab or a ceramic cylinder located between the electrodes define a gain volume. Surfaces of the ceramic slab or the ceramic cylinder are separated from the passivated surfaces of the electrodes by small gaps to prevent abrasion thereof. Reducing compressive forces that secure these components within the housing further reduces abrasion, thereby extending the operational lifetime of the gas laser.
H01S 3/032 - Détails de structure des tubes laser à décharge dans le gaz pour le confinement de la décharge, p. ex. par des caractéristiques particulières du tube pour la contraction de la décharge
H01S 3/038 - Électrodes, p. ex. forme, configuration ou composition particulières
H01S 3/0971 - Procédés ou appareils pour l'excitation, p. ex. pompage par décharge dans le gaz d'un laser à gaz excité transversalement
H01S 3/07 - Structure ou forme du milieu actif consistant en une pluralité de parties, p. ex. segments
H01S 3/081 - Structure ou forme des résonateurs optiques ou de leurs composants comprenant trois réflecteurs ou plus
H01S 3/223 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet caractérisés par le matériau utilisé comme milieu actif à gaz le gaz actif étant polyatomique, c.-à-d. contenant plusieurs atomes
H01S 3/03 - Détails de structure des tubes laser à décharge dans le gaz
2) or carbon monoxide (CO) gas laser includes two electrodes, which have passivated surfaces, within a sealed housing. Features in a ceramic slab or a ceramic cylinder located between the electrodes define a gain volume. Surfaces of the ceramic slab or the ceramic cylinder are separated from the passivated surfaces of the electrodes by small gaps to prevent abrasion thereof. Reducing compressive forces that secure these components within the housing further reduces abrasion, thereby extending the operational lifetime of the gas laser.
H01S 3/03 - Détails de structure des tubes laser à décharge dans le gaz
H01S 3/038 - Électrodes, p. ex. forme, configuration ou composition particulières
H01S 3/097 - Procédés ou appareils pour l'excitation, p. ex. pompage par décharge dans le gaz d'un laser à gaz
H01S 3/223 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet caractérisés par le matériau utilisé comme milieu actif à gaz le gaz actif étant polyatomique, c.-à-d. contenant plusieurs atomes
An optical parametric chirped-pulse amplifier includes first and second optical parametric amplifier stages that successively amplify a stretched signal beam. A pulsed laser provides a fundamental beam. The second amplifier stage is pumped by the full power of a second-harmonic beam that is generated from the fundamental beam. A residual fundamental beam is used to generate another second-harmonic beam that pumps the first amplifier stage.
H01S 3/091 - Procédés ou appareils pour l'excitation, p. ex. pompage utilisant le pompage optique
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
H01S 3/23 - Agencement de plusieurs lasers non prévu dans les groupes , p. ex. agencement en série de deux milieux actifs séparés
G02F 1/39 - Optique non linéaire pour la génération ou l'amplification paramétrique de la lumière, des infrarouges ou des ultraviolets
An optical parametric chirped-pulse amplifier includes first and second optical parametric amplifier stages that successively amplify a stretched signal beam. A pulsed laser provides a fundamental beam. The second amplifier stage is pumped by the full power of a second-harmonic beam that is generated from the fundamental beam. A residual fundamental beam is used to generate another second-harmonic beam that pumps the first amplifier stage.
A wavelength sensor for wavelength stabilization of a laser beam includes an etalon placed in the laser beam and tilted with respect to the laser beam. Reflected beams from the etalon form an interference pattern on a segmented photodetector having two detector segments. Output signals from the two detector segments are used to derive an error signal for a closed control loop to effect the wavelength stabilization.
H01S 5/0683 - Stabilisation des paramètres de sortie du laser en surveillant les paramètres optiques de sortie
G01J 9/02 - Mesure du déphasage des rayons lumineuxRecherche du degré de cohérenceMesure de la longueur d'onde des rayons lumineux par des méthodes interférométriques
A wavelength sensor for wavelength stabilization of a laser beam includes an etalon placed in the laser beam and tilted with respect to the laser beam. Reflected beams from the etalon form an interference pattern on a segmented photodetector having two detector segments. Output signals from the two detector segments are used to derive an error signal for a closed control loop to effect the wavelength stabilization.
H01S 3/13 - Stabilisation de paramètres de sortie de laser, p. ex. fréquence ou amplitude
H01S 5/065 - Accrochage de modesSuppression de modesSélection de modes
H01S 5/0687 - Stabilisation de la fréquence du laser
H01S 3/137 - Stabilisation de paramètres de sortie de laser, p. ex. fréquence ou amplitude par commande de dispositifs placés dans la cavité pour la stabilisation de la fréquence
H01S 3/139 - Stabilisation de paramètres de sortie de laser, p. ex. fréquence ou amplitude par commande de la position relative ou des propriétés réfléchissantes des réflecteurs de la cavité
H01S 3/08 - Structure ou forme des résonateurs optiques ou de leurs composants
A fiber laser producing a beam of ultrashort laser pulses at a repetition rate greater than 200 MHz includes a linear fiber resonator and a fiber branch. Ultrashort laser pulses are generated by passive mode-locking and circulate within the linear fiber resonator. Each circulating laser pulse is split into a portion that continues propagating in the linear fiber resonator and a complementary portion that propagates through the fiber branch and is then returned to the linear fiber resonator. The optical length of the linear fiber resonator is an integer multiple of the optical length of the fiber branch. The repetition rate of the ultrashort laser pulses is the reciprocal of the propagation time of the laser pulses through the fiber branch.
H01S 3/08 - Structure ou forme des résonateurs optiques ou de leurs composants
H01S 3/10 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation
H01S 3/1055 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation par commande de la position relative ou des propriétés réfléchissantes des réflecteurs de la cavité un des réflecteurs étant constitué par un réseau de diffraction
An apparatus for generating visible light including a laser source emitting a fundamental beam, an optically nonlinear crystal, and a seed source emitting a seed beam. The optically nonlinear crystal receives the fundamental beam. The fundamental beam propagates in the nonlinear crystal at a first phase-matching angle for second-harmonic generation. A portion of the fundamental beam is converted into a second-harmonic beam that propagates in the nonlinear crystal at the first phase-matching angle for optical parametric generation. The seed source emits a seed beam having a wavelength longer than the second-harmonic beam. The seed beam is directed into the nonlinear crystal and propagates at a second phase-matching angle for the optical parametric amplification. A portion of the second-harmonic beam is converted into a signal beam at the seed wavelength and an idler beam by the optical parametric amplification.
An apparatus includes a beam source, beam forming optics, a first focusing lens having a focal length, a second focusing lens having a focal length similar to the focal length of the first lens, and a lens translator configured to move the second lens transversely relative to the beam forming optics and to the first lens, and thereby move the elongated focus transversely. In some embodiments, the beam forming optics are positioned between the beam source and the first focusing lens, the first focusing lens is positioned between the beam forming optics and the second focusing lens, and the beam forming optics, the first focusing lens, and the second focusing lens are arranged to receive a beam of laser radiation from the beam source and to form the beam into an elongated focus.
An apparatus includes a beam source, beam forming optics, a first focusing lens having a focal length, a second focusing lens having a focal length similar to the focal length of the first lens, and a lens translator configured to move the second lens transversely relative to the beam forming optics and to the first lens, and thereby move the elongated focus transversely. In some embodiments, the beam forming optics are positioned between the beam source and the first focusing lens, the first focusing lens is positioned between the beam forming optics and the second focusing lens, and the beam forming optics, the first focusing lens, and the second focusing lens are arranged to receive a beam of laser radiation from the beam source and to form the beam into an elongated focus.
G02B 26/08 - Dispositifs ou dispositions optiques pour la commande de la lumière utilisant des éléments optiques mobiles ou déformables pour commander la direction de la lumière
G02B 27/09 - Mise en forme du faisceau, p. ex. changement de la section transversale, non prévue ailleurs
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/073 - Détermination de la configuration du spot laser
A pump reflector (10) for efficiently recycling unabsorbed pump radiation in a diode-pumped fiber laser includes a core (12) for guiding a laser beam, a pump cladding (14), and a tapered capillary tube (16). Pump radiation is adiabatically guided in the tapered capillary tube (16), which includes a mirror (28) that is reflective for the pump radiation. The pump reflector (10) may be packaged as a fiber component for copropagating or counter-propagating fiber laser amplifiers and resonators.
The invention concerns an apparatus and its use for laser welding. A laser welding apparatus comprise at least one first laser device, each providing at least one first optical feed fiber with a first laser beam; at least one second laser device, each providing at least one second optical feed fiber with a second laser beam; means for generating a composite laser beam comprising a first output laser beam and a second output laser beam for welding a workpiece; wherein the first output laser beam has a circular cross-section and the second output laser beam has an annular shape concentric to the first output laser beam. The second laser device is a fiber laser device or a fiber-coupled laser device. The apparatus is configured to form the second output laser beam at least on the basis of the second laser beam, and the second output laser beam comprises a first wavelength and a second wavelength having difference of at least 10 nanometers, or the second output laser beam has spectrum width of least 10 nanometers.
The invention relates to an optical assembly (100) comprising a first optical fiber (101) propagating coherent light in a predetermined direction (P) into an input end (110) of the optical assembly (100), said optical fiber having a core and a cladding; a heat sink (111) surrounding the optical fiber (101) at the input end (110); and a lens (120) arranged after the heat sink (111) in the propagating direction (P). The optical assembly (100) further comprises a filter (130) arranged after the lens (120), wherein the filter (130) has a reflective surface (131) arranged to transmit light having one or more desired wavelengths and to reflect one or more undesired wavelengths back through the lens (120). The invention further relates to a method for separating desired and undesired wavelengths.
G02B 6/42 - Couplage de guides de lumière avec des éléments opto-électroniques
G02B 6/293 - Moyens de couplage optique ayant des bus de données, c.-à-d. plusieurs guides d'ondes interconnectés et assurant un système bidirectionnel par nature en mélangeant et divisant les signaux avec des moyens de sélection de la longueur d'onde
G02B 6/32 - Moyens de couplage optique ayant des moyens de focalisation par lentilles
A method for laser keyhole welding of metal alloys is disclosed. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power in the center beam is initially ramped up and then ramped down, while the power in the annular beam is ramped down. Increasing the power in the center beam enables a controlled and prolonged contraction of the keyhole and melt pool, thereby preventing undesirable cracking.
A method for laser keyhole welding of metal alloys is disclosed. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power in the center beam is initially ramped up and then ramped down, while the power in the annular beam is ramped down. Increasing the power in the center beam enables a controlled and prolonged contraction of the keyhole and melt pool, thereby preventing undesirable cracking.
A method for laser keyhole welding of metal alloys is disclosed. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power in the center beam is initially ramped up and then ramped down, while the power in the annular beam is ramped down. Increasing the power in the center beam enables a controlled and prolonged contraction of the keyhole and melt pool, thereby preventing undesirable cracking.
An apparatus for cutting brittle material comprises an aspheric focusing lens, an aperture, and a laser-source generating a beam of pulsed laser-radiation. The aspheric lens and the aperture form the beam of pulsed laser-radiation into an elongated focus having a uniform intensity distribution along the optical axis of the aspheric focusing lens. The elongated focus extends through the full thickness of a workpiece made of a brittle material. The workpiece is cut by tracing the optical axis along a cutting line. Each pulse or burst of pulsed laser-radiation creates an extended defect through the full thickness of the workpiece.
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/073 - Détermination de la configuration du spot laser
B23K 26/00 - Travail par rayon laser, p. ex. soudage, découpage ou perçage
B23K 26/53 - Travail par transmission du faisceau laser à travers ou dans la pièce à travailler pour modifier ou reformer le matériau dans la pièce à travailler, p. ex. pour faire des fissures d'amorce de rupture
B23K 26/066 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples au moyen d'éléments optiques, p. ex. lentilles, miroirs ou prismes par utilisation de masques
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
B23K 26/08 - Dispositifs comportant un mouvement relatif entre le faisceau laser et la pièce
B23K 26/402 - Enlèvement de matière en tenant compte des propriétés du matériau à enlever en faisant intervenir des matériaux non métalliques, p. ex. des isolants
C03B 33/02 - Découpe ou fendage des feuilles de verreDispositifs ou machines à cet effet
G02B 27/09 - Mise en forme du faisceau, p. ex. changement de la section transversale, non prévue ailleurs
Laser annealing apparatus includes a plurality of frequency- tripled solid-state lasers, each delivering an output beam of radiation at a wavelength between 340 nm and 360 nm. Each output beam has a beam-quality factor (M2) greater of than 50 in one transverse axis and greater than 20 in another transverse axis. The output beams are combined and formed into a line-beam that is projected on a substrate being annealed. Each output beam contributes to the length of the line-beam.
H01S 3/11 - Blocage de modesCommutation-QAutres techniques d'impulsions géantes, p. ex. vidange de cavité
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
60.
DIODE-PUMPED SOLID-STATE LASER APPARATUS FOR LASER ANNEALING
Laser annealing apparatus includes a plurality of frequency-tripled solid-state lasers, each delivering an output beam of radiation at a wavelength between 340 nm and 360 nm. Each output beam has a beam-quality factor (M2) greater of than 50 in one transverse axis and greater than 20 in another transverse axis. The output beams are combined and formed into a line-beam that is projected on a substrate being annealed. Each output beam contributes to the length of the line-beam.
H01S 3/115 - Commutation-Q utilisant des dispositifs électro-optiques dans la cavité
H01S 3/08 - Structure ou forme des résonateurs optiques ou de leurs composants
H01S 3/0941 - Procédés ou appareils pour l'excitation, p. ex. pompage utilisant le pompage optique par de la lumière cohérente produite par un laser à semi-conducteur, p. ex. par une diode laser
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
B23K 26/064 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples au moyen d'éléments optiques, p. ex. lentilles, miroirs ou prismes
B23K 26/354 - Travail par rayon laser, p. ex. soudage, découpage ou perçage pour le traitement de surface par fusion
B23K 26/00 - Travail par rayon laser, p. ex. soudage, découpage ou perçage
A carbon dioxide gas-discharge slab-laser is assembled in a laser-housing. The laser-housing is formed from a hollow extrusion. An interior surface of the extrusion provides a ground electrode of the laser. Another live electrode is located within the extrusion, electrically insulated from and parallel to the ground electrode, forming a discharge-gap of the slab-laser. The electrodes are spaced apart by parallel ceramic strips. Neither the extrusion, nor the live electrode, include fluid coolant channels. The laser-housing is cooled by fluid-cooled plates attached to the outside thereof.
H01S 3/041 - Dispositions pour la gestion thermique pour des lasers à gaz
H01S 3/038 - Électrodes, p. ex. forme, configuration ou composition particulières
H01S 3/03 - Détails de structure des tubes laser à décharge dans le gaz
H01S 3/223 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet caractérisés par le matériau utilisé comme milieu actif à gaz le gaz actif étant polyatomique, c.-à-d. contenant plusieurs atomes
H01S 3/04 - Dispositions pour la gestion thermique
A source of high-radiance broad-band incoherent light includes an optical waveguide, having a core made of phosphor granules embedded in a matrix of glass and a cladding. The core having a relatively high refractive index and the cladding having a relatively low refractive index. The phosphor granules and the glass matrix having about the same refractive index. Radiation from one or more diode-lasers is injected into one end of the waveguide to energize the phosphor granules, producing broad-band incoherent light, which is confined and guided to an opposite end of the waveguide as output light.
A laser-radiation sensor includes a copper substrate on which is grown an oriented polycrystalline buffer layer surmounted by an oriented polycrystalline sensor-element of an anisotropic transverse thermoelectric material. An absorber layer, thermally connected to the sensor-element, is heated by laser-radiation to be measured and communicates the heat to the sensor-element, causing a thermal gradient across the sensor-element. Spaced-apart electrodes in electrical contact with the sensor-element sense a voltage corresponding to the thermal gradient as a measure of the incident laser-radiation power.
G01J 1/42 - Photométrie, p. ex. posemètres photographiques en utilisant des détecteurs électriques de radiations
H01L 31/0368 - Dispositifs à semi-conducteurs sensibles aux rayons infrarouges, à la lumière, au rayonnement électromagnétique d'ondes plus courtes, ou au rayonnement corpusculaire, et spécialement adaptés, soit comme convertisseurs de l'énergie dudit rayonnement e; Procédés ou appareils spécialement adaptés à la fabrication ou au traitement de ces dispositifs ou de leurs parties constitutives; Leurs détails caractérisés par leurs corps semi-conducteurs caractérisés par leur structure cristalline ou par l'orientation particulière des plans cristallins comprenant des semi-conducteurs polycristallins
G01J 5/12 - Pyrométrie des radiations, p. ex. thermométrie infrarouge ou optique en utilisant des détecteurs électriques de radiations en utilisant des éléments thermoélectriques, p. ex. des thermocouples
A pump reflector for efficiently recycling unabsorbed pump radiation in a diode-pumped fiber laser includes a core for guiding a laser beam, a pump cladding, and a tapered capillary tube. Pump radiation is adiabatically guided in the tapered capillary tube, which includes a mirror that is reflective for the pump radiation. The pump reflector may be packaged as a fiber component for co-propagating or counter-propagating fiber laser amplifiers and resonators.
An apparatus for generating visible light including a laser source emitting a fundamental beam, an optically nonlinear crystal, and a seed source emitting a seed beam. The optically nonlinear crystal receives the fundamental beam. The fundamental beam propagates in the nonlinear crystal at a first phase-matching angle for second-harmonic generation. A portion of the fundamental beam is converted into a second-harmonic beam that propagates in the nonlinear crystal at the first phase-matching angle for optical parametric generation. The seed source emits a seed beam having a wavelength longer than the second-harmonic beam. The seed beam is directed into the nonlinear crystal and propagates at a second phase-matching angle for the optical parametric amplification. A portion of the second-harmonic beam is converted into a signal beam at the seed wavelength and an idler beam by the optical parametric amplification.
A third-harmonic conversion arrangement includes a second-harmonic generating crystal and a third-harmonic generating crystal arranged in a polarization loop. The polarization loop, which includes a plurality of mirrors, a polarization-selective reflector, and a polarization rotator, causes plane-polarized fundamental-wavelength radiation being converted to make two passes through the crystals in orthogonally-opposed polarization orientations.
G02B 27/09 - Mise en forme du faisceau, p. ex. changement de la section transversale, non prévue ailleurs
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
H01S 3/11 - Blocage de modesCommutation-QAutres techniques d'impulsions géantes, p. ex. vidange de cavité
67.
THIRD-HARMONIC GENERATING APPARATUS FOR LASER-RADIATION
A third-harmonic conversion arrangement includes a second-harmonic generating crystal and a third-harmonic generating crystal arranged in a polarization loop. The polarization loop causes plane-polarized fundamental-wavelength radiation being converted to make two passes through the crystals in orthogonally-opposed polarization orientations.
A laser master-oscillator power-amplifier (MOPA) is operated to provide successive bursts of ultrashort pulses. The pulse-bursts are selected by an optical modulator from a pulse train delivered by the master oscillator prior to amplification in the power amplifier. The optical modulator has a selectively variable transmission specified by an analog voltage signal having a stepped waveform. The voltage signal is delivered by a sequentially-switched parallel switch-array connected in parallel with a parallel DAC having multiple parallel DC voltage outputs corresponding to steps of the stepped waveform.
H01S 3/10 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
H01S 5/062 - Dispositions pour commander les paramètres de sortie du laser, p. ex. en agissant sur le milieu actif en faisant varier le potentiel des électrodes
A laser master-oscillator power-amplifier (MOPA) is operated to provide successive bursts of ultrashort pulses. The pulse-bursts are selected by an optical modulator from a pulse train delivered by the master oscillator prior to amplification in the power amplifier. The optical modulator has a selectively variable transmission specified by an analog voltage signal having a stepped waveform. The voltage signal is delivered by a sequentially-switched parallel switch-array connected in parallel with a parallel DAC having multiple parallel DC voltage outputs corresponding to steps of the stepped waveform.
H01S 3/106 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation par commande de dispositifs placés dans la cavité
H01S 5/065 - Accrochage de modesSuppression de modesSélection de modes
The invention concerns an apparatus and its use for laser processing. The invention also concerns a method and an optical component. According to the invention, at a first laser device, providing a first optical feed fiber and a second laser device providing a second optical feed fiber is provided. A beam combining means connected to the first and second feed fibers and to a multi-core optical fiber is adapted to form a composite laser beam by having the first optical feed fiber aligned with a first core of the multi-core optical fiber and the second optical feed fiber aligned with at least one second core of the multi-core optical fiber. The first and second cores outputs a composite laser beam to a workpiece to be processed. A control unit controls power density of at least one of first and second laser beams of the composite laser beam in at least one of: in response to approaching a change point in direction of cutting progression and to cause change in relation between the power density of the first output laser beam and power density of the second output laser beam in accordance with thickness of the workpiece being cut.
G02B 6/036 - Fibres optiques avec revêtement le noyau ou le revêtement comprenant des couches multiples
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/073 - Détermination de la configuration du spot laser
B23K 26/38 - Enlèvement de matière par perçage ou découpage
G02B 6/28 - Moyens de couplage optique ayant des bus de données, c.-à-d. plusieurs guides d'ondes interconnectés et assurant un système bidirectionnel par nature en mélangeant et divisant les signaux
A carbon dioxide gas-discharge slab-laser is assembled in a laser-housing. The laser-housing is formed from a hollow extrusion. An interior surface of the extrusion provides a ground electrode of the laser. Another live electrode is located within the extrusion, electrically insulated from and parallel to the ground electrode, forming a discharge-gap of the slab-laser. The electrodes are spaced apart by parallel ceramic strips. Neither the extrusion, nor the live electrode, include any direct fluid-cooling means. The laser-housing is cooled by fluid-cooled plates attached to the outside thereof.
H01S 3/041 - Dispositions pour la gestion thermique pour des lasers à gaz
H01S 3/038 - Électrodes, p. ex. forme, configuration ou composition particulières
H01S 3/03 - Détails de structure des tubes laser à décharge dans le gaz
H01S 3/223 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet caractérisés par le matériau utilisé comme milieu actif à gaz le gaz actif étant polyatomique, c.-à-d. contenant plusieurs atomes
H01S 3/04 - Dispositions pour la gestion thermique
A carbon dioxide gas-discharge slab-laser is assembled in a laser-housing. The laser-housing is formed from a hollow extrusion. An interior surface of the extrusion provides a ground electrode of the laser. Another live electrode is located within the extrusion, electrically insulated from and parallel to the ground electrode, forming a discharge-gap of the slab-laser. The electrodes are spaced apart by parallel ceramic strips. Neither the extrusion, nor the live electrode, include any direct fluid-cooling means. The laser-housing is cooled by fluid-cooled plates attached to the outside thereof.
An aluminum covered with an anodically formed aluminum oxide layer is marked by repeated bursts of two or more individual laser pulses. The intensity of the individual pulses in the bursts is kept below a level experimentally determined to compromise the integrity of the aluminum oxide layer. The collective fluence in a burst is sufficient to mark the aluminum, but not sufficient to compromise the integrity of the oxide layer.
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
B23K 26/356 - Travail par rayon laser, p. ex. soudage, découpage ou perçage pour le traitement de surface par traitement par choc
B23K 26/359 - Travail par rayon laser, p. ex. soudage, découpage ou perçage pour le traitement de surface en formant une ligne ou un motif linéaire, p. ex. une ligne en pointillés d'amorce de rupture
An anamorphic three-element objective lens projects a plurality of beams of different wavelengths and different diameters into an elongated focal spot in a working- plane. In one transverse direction of the lens, the beams are tightly focused with equal beam-waist widths in the working-plane, defining a height of the focal spot. In another transverse direction, the different beams are focused progressively beyond the working- plane such that the beams have a common beam-width in the working-plane, thereby defining a width of the focal spot.
G02B 9/16 - Objectifs optiques caractérisés à la fois par le nombre de leurs composants et la façon dont ceux-ci sont disposés selon leur signe, c.-à-d. + ou — ayant uniquement trois composants disposés + — + tous trois étant simples
G02B 13/00 - Objectifs optiques spécialement conçus pour les emplois spécifiés ci-dessous
An anamorphic three-element objective lens projects a plurality of beams of different wavelengths and different diameters into an elongated focal spot in a working-plane. In one transverse direction of the lens, the beams are tightly focused with equal beam-waist widths in the working-plane, defining a height of the focal spot. In another transverse direction, the different beams are focused progressively beyond the working-plane such that the beams have a common beam-width in the working-plane, thereby defining a width of the focal spot.
G02B 27/14 - Systèmes divisant ou combinant des faisceaux fonctionnant uniquement par réflexion
G02B 13/14 - Objectifs optiques spécialement conçus pour les emplois spécifiés ci-dessous à utiliser avec des radiations infrarouges ou ultraviolettes
G02B 27/18 - Systèmes ou appareils optiques non prévus dans aucun des groupes , pour projection optique, p. ex. combinaison de miroir, de condensateur et d'objectif
G02B 23/04 - Télescopes ou lunettes d'approche, p. ex. jumellesPériscopesInstruments pour voir à l'intérieur de corps creuxViseursPointage optique ou appareils de visée comprenant des prismes ou des miroirs afin de partager ou de combiner des faisceaux lumineux, p. ex. munis d'oculaires pour plus d'un observateur
G02B 27/10 - Systèmes divisant ou combinant des faisceaux
G02B 9/16 - Objectifs optiques caractérisés à la fois par le nombre de leurs composants et la façon dont ceux-ci sont disposés selon leur signe, c.-à-d. + ou — ayant uniquement trois composants disposés + — + tous trois étant simples
G02B 27/09 - Mise en forme du faisceau, p. ex. changement de la section transversale, non prévue ailleurs
G01N 15/14 - Techniques de recherche optique, p. ex. cytométrie en flux
A61B 5/00 - Mesure servant à établir un diagnostic Identification des individus
G01N 15/10 - Recherche de particules individuelles
The invention concerns an apparatus and its use for laser welding. A laser welding apparatus comprises at least one first laser device (30), each providing at least one first optical feed fiber (32) with a first laser beam; at least one second laser device (31), each providing at least one second optical feed fiber (33) with a second laser beam; means for generating a composite laser beam comprising a first output laser beam and a second output laser beam (2) for welding a workpiece (21); wherein the first output laser beam has a circular cross-section and the second output laser beam (2) has an annular shape concentric to the first output laser beam. The second laser device (31) is a fiber laser device or a fiber-coupled laser device. The apparatus is configured to form the second output laser beam (2) at least on the basis of the second laser beam, and the second output laser beam (2) comprises a first wavelength and a second wavelength having difference of at least 10 nanometers, or the second output laser beam (2) has spectrum width of least 10 nanometers.
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/064 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples au moyen d'éléments optiques, p. ex. lentilles, miroirs ou prismes
B23K 26/073 - Détermination de la configuration du spot laser
Apparatus for distance gauging in laser material processing includes a source of laser-radiation, an electrically-conductive focusing assembly, a constant-current source, and a voltmeter. The focusing assembly focuses laser-radiation towards an electrically conductive workpiece being processed. The focusing assembly and the workpiece form a capacitive sensor. The constant current source provides a constant electrical current to the focusing assembly for a constant time. The focusing assembly and the workpiece are separated by a distance that is proportional to a change in voltage measured on the focusing assembly during the constant time.
B23K 26/04 - Alignement, pointage ou focalisation automatique du faisceau laser, p. ex. en utilisant la lumière rétrodiffusée
G01B 7/02 - Dispositions pour la mesure caractérisées par l'utilisation de techniques électriques ou magnétiques pour mesurer la longueur, la largeur ou l'épaisseur
Apparatus for distance gauging in laser material processing includes a source of laser-radiation, an electrically-conductive focusing assembly, a constant-current source, and a voltmeter. The focusing assembly focuses laser-radiation towards an electrically conductive workpiece being processed. The focusing assembly and the workpiece form a capacitive sensor. The constant current source provides a constant electrical current to the focusing assembly for a constant time. The focusing assembly and the workpiece are separated by a distance that is proportional to a change in voltage measured on the focusing assembly during the constant time.
B23K 26/04 - Alignement, pointage ou focalisation automatique du faisceau laser, p. ex. en utilisant la lumière rétrodiffusée
G01B 7/02 - Dispositions pour la mesure caractérisées par l'utilisation de techniques électriques ou magnétiques pour mesurer la longueur, la largeur ou l'épaisseur
Apparatus for distance gauging in laser material processing includes a source of laser-radiation, an electrically-conductive focusing assembly, a constant-current source, and a voltmeter. The focusing assembly focuses laser-radiation towards an electrically conductive workpiece being processed. The focusing assembly and the workpiece form a capacitive sensor. The constant current source provides a constant electrical current to the focusing assembly for a constant time. The focusing assembly and the workpiece are separated by a distance that is proportional to a change in voltage measured on the focusing assembly during the constant time.
B23K 26/04 - Alignement, pointage ou focalisation automatique du faisceau laser, p. ex. en utilisant la lumière rétrodiffusée
G01B 7/14 - Dispositions pour la mesure caractérisées par l'utilisation de techniques électriques ou magnétiques pour mesurer la distance ou la marge entre des objets ou des ouvertures espacés
B23K 26/38 - Enlèvement de matière par perçage ou découpage
The invention concerns an apparatus and a method for laser processing. There is provided at least one first laser beam from at least one first optical feed fiber connected to at least one first laser device and at least one second laser beam from at least one second optical feed fiber connected to at least one second laser device. Said first and second laser beams are combined in a multi-core optical fiber. Said first core of said multi-core optical fiber has a circular cross-section, and said second core has an annular shape concentric to said first core. A composite laser beam comprising first and second output beams is directed from said multi-core optical fiber to a workpiece with overlapping elements to be welded.
The invention relates to an optical assembly (100) comprising a first optical fiber (101) propagating coherent light in a predetermined direction (P) into an input end (110) of the optical assembly (100), said optical fiber having a core and a cladding; a heat sink (111) surrounding the optical fiber (101) at the input end (110); and a lens (120) arranged after the heat sink (111) in the propagating direction (P).The optical assembly (100) further comprises a filter (130) arranged after the lens (120), wherein the filter (130) has a reflective surface (131) arranged to transmit light having one or more desired wavelengths and to reflect one or more undesired wavelengths back through the lens (120). The invention further relates to a method for separating desired and undesired wavelengths.
Laser-apparatus includes a fiber-MOPA arranged to deliver amplified seed optical pulses having a wavelength of about 1043 nanometers to a multi-pass ytterbium-doped yttrium aluminum garnet solid-state optical amplifier for further amplification.
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
H01S 3/23 - Agencement de plusieurs lasers non prévu dans les groupes , p. ex. agencement en série de deux milieux actifs séparés
H01S 3/0941 - Procédés ou appareils pour l'excitation, p. ex. pompage utilisant le pompage optique par de la lumière cohérente produite par un laser à semi-conducteur, p. ex. par une diode laser
H01S 3/10 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation
83.
High power sub-400 femtosecond MOPA with solid-state power amplifier
Laser-apparatus includes a fiber-MOPA arranged to deliver amplified seed optical pulses having a wavelength of about 1043 nanometers to a multi-pass ytterbium-doped yttrium aluminum garnet solid-state optical amplifier for further amplification.
A fiber-laser includes a gain-fiber in a laser-resonator. A polarizer is located in the laser-resonator at an end thereof, causing the output of the fiber-laser to be linearly polarized. A wavelength-selective element is also included in the laser-resonator for selecting an output wavelength of the fiber-laser from within a gain-bandwidth of the gain-fiber.
A fiber-laser includes a gain-fiber in a laser-resonator. A polarizer is located in the laser-resonator at an end thereof, causing the output of the fiber-laser to be linearly polarized. A wavelength-selective element is also included in the laser-resonator for selecting an output wavelength of the fiber-laser from within a gain-bandwidth of the gain-fiber.
H01S 3/094 - Procédés ou appareils pour l'excitation, p. ex. pompage utilisant le pompage optique par de la lumière cohérente
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
H01S 3/23 - Agencement de plusieurs lasers non prévu dans les groupes , p. ex. agencement en série de deux milieux actifs séparés
An intra-cavity frequency-tripled OPS laser has a laser-resonator including two optically nonlinear crystals arranged for type-I frequency conversion. One of the crystals generates horizontally polarized second-harmonic radiation from vertically plane-polarized fundamental-wavelength radiation circulating in the laser-resonator. A birefringent filter is located between the optically nonlinear crystals. The birefringent filter selects the fundamental-wavelength, establishes the vertical polarization-orientation, and selectively rotates the polarization-orientation of the second-harmonic radiation from horizontal to vertical. The vertically polarized fundamental and second-harmonic radiations are type-I sum-frequency mixed by the other optically nonlinear crystal.
H01S 3/10 - Commande de l'intensité, de la fréquence, de la phase, de la polarisation ou de la direction du rayonnement, p. ex. commutation, ouverture de porte, modulation ou démodulation
H01S 3/109 - Multiplication de la fréquence, p. ex. génération d'harmoniques
H01S 3/081 - Structure ou forme des résonateurs optiques ou de leurs composants comprenant trois réflecteurs ou plus
H01S 3/13 - Stabilisation de paramètres de sortie de laser, p. ex. fréquence ou amplitude
H01S 3/08 - Structure ou forme des résonateurs optiques ou de leurs composants
H01S 3/0941 - Procédés ou appareils pour l'excitation, p. ex. pompage utilisant le pompage optique par de la lumière cohérente produite par un laser à semi-conducteur, p. ex. par une diode laser
The invention concerns an apparatus and its use for laser processing. The invention also concerns a method. According to the invention, at a first laser device (30), providing a first optical feed fiber (32) and at a second laser device (31 ) providing a second optical feed fiber (33). A beam combining means (34) connected to the first and second feed fibers and to a multi-core optical fiber (35) is adapted to form a composite laser beam by having the first optical feed fiber (32) aligned with a first core of the multi-core optical fiber and the second optical feed fiber aligned with at least one second core of the multi-core optical fiber (35). The first and second cores output a composite laser beam (2) to a workpiece (21) to be processed. A control unit (10) controls power density of at least one of first and second laser beams of the composite laser beam in at least one of: in response to approaching a change point (22) in direction of cutting progression and to cause change in relation between the power density of the first output laser beam and power density of the second output laser beam in accordance with thickness of the workpiece (21) being cut.
G02B 6/04 - Guides de lumièreDétails de structure de dispositions comprenant des guides de lumière et d'autres éléments optiques, p. ex. des moyens de couplage formés par des faisceaux de fibres
88.
Laser processing apparatus and method and an optical component therefor
An apparatus and its use for laser processing along with a method and an optical component. A first laser device provides a first optical feed fiber and a second laser device provides a second optical feed fiber. A beam combining means connected to the first and second feed fibers and to a multi-core optical fiber is adapted to form a composite laser beam by having the first optical feed fiber aligned with a first core of the multi-core optical fiber and the second optical feed fiber aligned with at least one second core of the multi-core optical fiber. The first and second cores outputs a composite laser beam to a workpiece to be processed. A control unit individually controls the power density of the output laser beams.
G02B 6/28 - Moyens de couplage optique ayant des bus de données, c.-à-d. plusieurs guides d'ondes interconnectés et assurant un système bidirectionnel par nature en mélangeant et divisant les signaux
89.
LASER APPARATUS FOR CUTTING BRITTLE MATERIAL WITH ASPHERIC FOCUSING MEANS AND A BEAM EXPANDER
An apparatus for cutting brittle material comprises beam expander (18) in combination with an aspheric focusing lens (22), an aperture (CA), and a laser-source (12) generating a beam (14) of pulsed laser-radiation. The aspheric lens (22) and the aperture (CA) form the beam (24) of pulsed laser-radiation into an elongated focus having a uniform intensity distribution along the optical axis of the aspheric focusing lens (22). The elongated focus extends through the full thickness of a workpiece (38) made of a brittle material. The workpiece (38) is cut by tracing the optical axis along a cutting line. Each pulse or burst of pulsed laser-radiation creates an extended defect through the full thickness of the workpiece (38).
B23K 26/00 - Travail par rayon laser, p. ex. soudage, découpage ou perçage
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/073 - Détermination de la configuration du spot laser
B23K 26/08 - Dispositifs comportant un mouvement relatif entre le faisceau laser et la pièce
C03B 33/09 - Sectionnement du verre refroidi par chocs thermiques
B23K 26/53 - Travail par transmission du faisceau laser à travers ou dans la pièce à travailler pour modifier ou reformer le matériau dans la pièce à travailler, p. ex. pour faire des fissures d'amorce de rupture
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
B23K 26/066 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples au moyen d'éléments optiques, p. ex. lentilles, miroirs ou prismes par utilisation de masques
B23K 103/00 - Matières à braser, souder ou découper
An apparatus for cutting brittle material comprises an aspheric focusing lens, an aperture, and a laser-source generating a beam of pulsed laser-radiation. The aspheric lens and the aperture form the beam of pulsed laser-radiation into an elongated focus having a uniform intensity distribution along the optical axis of the aspheric focusing lens. The elongated focus extends through the full thickness of a workpiece made of a brittle material. The workpiece is cut by tracing the optical axis along a cutting line. Each pulse or burst of pulsed laser-radiation creates an extended defect through the full thickness of the workpiece.
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/073 - Détermination de la configuration du spot laser
B23K 26/00 - Travail par rayon laser, p. ex. soudage, découpage ou perçage
B23K 26/53 - Travail par transmission du faisceau laser à travers ou dans la pièce à travailler pour modifier ou reformer le matériau dans la pièce à travailler, p. ex. pour faire des fissures d'amorce de rupture
B23K 26/066 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples au moyen d'éléments optiques, p. ex. lentilles, miroirs ou prismes par utilisation de masques
B23K 26/0622 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples par commande directe du faisceau laser par impulsions de mise en forme
B23K 26/08 - Dispositifs comportant un mouvement relatif entre le faisceau laser et la pièce
B23K 26/402 - Enlèvement de matière en tenant compte des propriétés du matériau à enlever en faisant intervenir des matériaux non métalliques, p. ex. des isolants
C03B 33/02 - Découpe ou fendage des feuilles de verreDispositifs ou machines à cet effet
G02B 27/09 - Mise en forme du faisceau, p. ex. changement de la section transversale, non prévue ailleurs
A mirror is used to form a beam of laser-radiation having a uniform intensity distribution from a beam of laser-radiation having a non-uniform intensity distribution. The mirror has a reflective surface that has a compound shape, which is two inclined surfaces joined by a rounded apex. The compound-mirror is achromatic and can form a uniform intensity distribution from a polychromatic beam of laser-radiation. The uniform intensity distribution may be an isotropic distribution or a flat-top distribution in a plane. The non-uniform intensity distribution may be a Gaussian distribution from a laser source.
A mirror is used to form a beam of laser-radiation having a uniform intensity distribution from a beam of laser-radiation having a non-uniform intensity distribution. The mirror has a reflective surface that has a compound shape, which is two inclined surfaces joined by a rounded apex. The compound-mirror is achromatic and can form a uniform intensity distribution from a polychromatic beam of laser-radiation. The uniform intensity distribution may be an isotropic distribution or a flat-top distribution in a plane. The non-uniform intensity distribution may be a Gaussian distribution from a laser source.
A laser-radiation detector is formed from a plurality of layers supported on a substrate. The plurality of layers includes a reflective metal layer and an oriented polycrystalline sensor-layer positioned between the metal layer and the substrate.
G01J 5/06 - Dispositions pour éliminer les effets des radiations perturbatricesDispositions pour compenser les changements de la sensibilité
G01J 5/12 - Pyrométrie des radiations, p. ex. thermométrie infrarouge ou optique en utilisant des détecteurs électriques de radiations en utilisant des éléments thermoélectriques, p. ex. des thermocouples
Apparatus (10) for generating ultraviolet (UV) pulsed laser-radiation for material-processing includes a laser-source (20) providing infrared (IR) pulsed laser-radiation and a frequency-conversion module (28). A lithium tetraborate (Li2B4O7) crystal (72) located within the frequency-conversion module (28) converts the IR pulsed laser-radiation to UV pulsed laser-radiation by non-linear harmonic generation. The frequency-conversion module (28) is an airtight enclosure that may be evacuated or contain a dry gas. A flexible optical fiber-assembly (24) transports the IR pulsed laser-radiation from the laser-source to the frequency-conversion module.
7) crystal located within the frequency-conversion module converts the IR pulsed laser-radiation to UV pulsed laser-radiation by non-linear harmonic generation. The frequency-conversion module is an airtight enclosure that may be evacuated or contain a dry gas. A flexible optical fiber-assembly transports the IR pulsed laser-radiation from the laser-source to the frequency-conversion module.
G02B 26/08 - Dispositifs ou dispositions optiques pour la commande de la lumière utilisant des éléments optiques mobiles ou déformables pour commander la direction de la lumière
G02F 1/355 - Optique non linéaire caractérisée par les matériaux utilisés
H01S 3/00 - Lasers, c.-à-d. dispositifs utilisant l'émission stimulée de rayonnement électromagnétique dans la gamme de l’infrarouge, du visible ou de l’ultraviolet
A method of delivering a beam of laser-radiation to a workpiece for processing the workpiece comprises transmitting the beam twice through an inactive acousto-optic modulator (AOM) crystal in opposite zero-order directions of the AOM at separate locations on the AOM crystal, before delivering the beam to the workpiece. When laser-radiation is to be blocked from reaching the workpiece, the AOM is activated.
G02F 1/33 - Dispositifs de déflexion acousto-optique
B23K 26/082 - Systèmes de balayage, c.-à-d. des dispositifs comportant un mouvement relatif entre le faisceau laser et la tête du laser
B23K 26/06 - Mise en forme du faisceau laser, p. ex. à l’aide de masques ou de foyers multiples
B23K 26/02 - Mise en place ou surveillance de la pièce à travailler, p. ex. par rapport au point d'impactAlignement, pointage ou focalisation du faisceau laser
A method of delivering a beam of laser-radiation to a workpiece for processing the workpiece comprises transmitting the beam twice through an acousto-optic modulator (AOM) crystal in opposite zero-order directions of the AOM at separate locations on the AOM crystal, before delivering the beam to the workpiece.
B23K 26/02 - Mise en place ou surveillance de la pièce à travailler, p. ex. par rapport au point d'impactAlignement, pointage ou focalisation du faisceau laser
G02F 1/11 - Dispositifs ou dispositions pour la commande de l'intensité, de la couleur, de la phase, de la polarisation ou de la direction de la lumière arrivant d'une source lumineuse indépendante, p. ex. commutation, ouverture de porte ou modulationOptique non linéaire pour la commande de l'intensité, de la phase, de la polarisation ou de la couleur basés sur des éléments acousto-optiques, p. ex. en utilisant la diffraction variable par des ondes sonores ou des vibrations mécaniques analogues
98.
APPARATUS FOR GENERATING A LINE-BEAM FROM A DIODE-LASER ARRAY
An apparatus for generating a line beam (26) includes a diode laser bar (20), a linear microlens array (34) and a plurality of lenses (30, 32, 36, 38) spaced apart and arranged along an optical axis. The linear microlens array (34) and the lenses (30, 32, 36, 38) shape laser radiation emitted by the diode laser bar (20) to form a uniform line beam (26) in an illumination plane (28). The lenses (30, 32, 36, 38) project a far-field image of the diode laser bar (20) onto an image plane (62) proximate to the illumination plane (28). The diode laser bar (20) is rotated from parallel alignment with the linear microlens array (34) for providing uniform line beam illumination over a range of locations along the optical axis.
In a flow cytometer, an objective lens (20) focuses in a common plane (P) an input laser-beam having four different wavelengths. The objective (20) consists of three single-lenses (CL1, CL2, FFL), the two first ones (CL1, CL2) being cylindrical for shaping and reducing the size of the input laser-beam, the third one (FFL) being spherical to focus the reduced-size laser-beam in the common plane (P).
G02B 9/16 - Objectifs optiques caractérisés à la fois par le nombre de leurs composants et la façon dont ceux-ci sont disposés selon leur signe, c.-à-d. + ou — ayant uniquement trois composants disposés + — + tous trois étant simples
A61B 18/20 - Instruments, dispositifs ou procédés chirurgicaux pour transférer des formes non mécaniques d'énergie vers le corps ou à partir de celui-ci par application de radiations électromagnétiques, p. ex. de micro-ondes en utilisant des lasers
G02B 13/00 - Objectifs optiques spécialement conçus pour les emplois spécifiés ci-dessous
In a flow cytometer, an objective lens (20) focuses in a common plane (P) an input laser-beam having four different wavelengths. The objective (20) consists of three single-lenses (CL1, CL2, FFL), the two first ones (CL1, CL2) being cylindrical for shaping and reducing the size of the input laser-beam, the third one (FFL) being spherical to focus the reduced-size laser-beam in the common plane (P).
G02B 9/16 - Objectifs optiques caractérisés à la fois par le nombre de leurs composants et la façon dont ceux-ci sont disposés selon leur signe, c.-à-d. + ou — ayant uniquement trois composants disposés + — + tous trois étant simples
G02B 13/00 - Objectifs optiques spécialement conçus pour les emplois spécifiés ci-dessous
G02B 27/09 - Mise en forme du faisceau, p. ex. changement de la section transversale, non prévue ailleurs
G01N 15/14 - Techniques de recherche optique, p. ex. cytométrie en flux
A61B 18/20 - Instruments, dispositifs ou procédés chirurgicaux pour transférer des formes non mécaniques d'énergie vers le corps ou à partir de celui-ci par application de radiations électromagnétiques, p. ex. de micro-ondes en utilisant des lasers
