A tunable laser assembly housed in a single enclosure and a method of control is described wherein the tunable laser, pump and semiconductor optical amplifier do not share a common optical axis but are all aligned to optical waveguides on an intervening planar lightwave circuit (PLC). Wavelength monitoring circuity is included on the PLC to enable monitoring and control of the tunable laser center wavelength and optical bandwidth. The design of the PLC does not introduce perturbations into the swept-source laser output spectrum that would cause artifacts in imaging applications such as optical coherence tomography (OCT).
A61B 5/00 - Measuring for diagnostic purposes Identification of persons
H01S 5/02251 - Out-coupling of light using optical fibres
H01S 5/02326 - Arrangements for relative positioning of laser diodes and optical components, e.g. grooves in the mount to fix optical fibres or lenses
H01S 5/183 - Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
A tunable laser assembly housed in a single enclosure and a method of control is described wherein the tunable laser, pump and semiconductor optical amplifier do not share a common optical axis but are all aligned to optical waveguides on an intervening planar lightwave circuit (PLC). Wavelength monitoring circuitry is included on the PLC to enable monitoring and control of the tunable laser center wavelength and optical bandwidth. The design of the PLC does not introduce perturbations into the swept-source laser output spectrum that would cause artifacts in imaging applications such as optical coherence tomography (OCT).
H01S 5/0683 - Stabilisation of laser output parameters by monitoring the optical output parameters
H01S 5/183 - Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
A tunable laser assembly housed in a single enclosure and a method of control is described wherein the tunable laser, pump and semiconductor optical amplifier do not share a common optical axis but are all aligned to optical waveguides on an intervening planar lightwave circuit (PLC). Wavelength monitoring circuitry is included on the PLC to enable monitoring and control of the tunable laser center wavelength and optical bandwidth. The design of the PLC does not introduce perturbations into the swept-source laser output spectrum that would cause artifacts in imaging applications such as optical coherence tomography (OCT).
H01S 3/13 - Stabilisation of laser output parameters, e.g. frequency or amplitude
G01B 9/02004 - Interferometers characterised by controlling or generating intrinsic radiation properties using two or more frequencies using frequency scans
G01B 9/02091 - Tomographic interferometers, e.g. based on optical coherence
H01S 5/183 - Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
A tunable laser assembly housed in a single enclosure and a method of control is described that provides high-speed monitoring and control of the spectral properties of widely tunable lasers, such as MEMS-tunable VCSELs, with an optical configuration that does not introduce perturbations into the swept-source laser output spectrum that would cause artifacts in imaging applications such as optical coherence tomography (OCT).
ABSTRACT A tunable laser assembly housed in a single enclosure and a method of control is described that provides high-speed monitoring and control of the spectral properties of widely tunable lasers, such as MEMS-tunable VCSELs, with an optical configuration that does not introduce perturbations into the swept-source laser output spectrum that would cause artifacts in imaging applications such as optical coherence tomography (OCT). Date Recue/Date Received 2021-01-26
H01S 5/068 - Stabilisation of laser output parameters
H01S 5/10 - Construction or shape of the optical resonator
H01S 5/183 - Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
Disclosed are the method and system to derive the wavelength/frequency information covering wide wavelength or frequency range. Its practical applications include both fixed wavelength optical signal and wide bandwidth tunable or non-tunable optical signal, where the wavelength/frequency information is necessary for optical signal calibration, control, and monitoring, optical communications, and data processing. The approach has a "self-compensation" feature which is preferred to improve the accuracy of the extracted wavelength or frequency information even though there are components in the system having strong wavelength or frequency dependence in the wide wavelength or frequency range. The method is generic which can be realized in free space, fiber, or photonic integrated circuit (PIC).
Disclosed are the method and system to derive the wavelength/frequency information covering wide wavelength or frequency range. Its practical applications include both fixed wavelength optical signal and wide bandwidth tunable or non-tunable optical signal, where the wavelength/frequency information is necessary for optical signal calibration, control, and monitoring, optical communications, and data processing. The approach has a “self-compensation” feature which is preferred to improve the accuracy of the extracted wavelength or frequency information even though there are components in the system having strong wavelength or frequency dependence in the wide wavelength or frequency range. The method is generic which can be realized in free space, fiber, or photonic integrated circuit (PIC).
An interband cascade laser including: a ridge waveguide having alternating first and second regions; wherein the first region has a constant width, and the second region has a width that matches that of the first region at boundaries between the first region and the second region, and the width of the second region increases to a maximum that is larger than the width of the first region, such that a partially-corrugated sidewall along each side of the ridge waveguide is formed; wherein the first region comprises a grating structure, and due to periodic nature of the first region, the grating structure is in a form of a sampled grating; and wherein the partially-corrugated sidewall increases waveguide losses for radiation in higher order lateral modes as compared to the fundamental waveguide mode.
Disclosed is a laser source capable of producing mid-IR laser radiation comprises growing a first core structure on a substrate, etching away the first core structure in one or more locations, and growing a second core structure on the substrate. At least one of the core structures comprises a quantum cascade gain medium emitting at a frequency within the range from 3-14 μm. Also disclosed is a laser source capable of producing mid-IR laser radiation comprising a quantum-cascade core positioned on a substrate for emitting within the range from 3-14 μm and a second core on the substrate positioned in-plane relative to the first core. The second core is one of a) a passive waveguide core b) a second quantum-cascade core and c) a semiconductor active core region.
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
H01S 5/026 - Monolithically integrated components, e.g. waveguides, monitoring photo-detectors or drivers
H01S 5/40 - Arrangement of two or more semiconductor lasers, not provided for in groups
H01S 5/343 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser
H01S 5/06 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
Concatenated distributed feedback lasers having novel waveguides are disclosed. The waveguides allow for coupling of the laser beam between active and passive waveguide structures and improved device design and output efficiency. Methods of making along with methods of using such devices are also disclosed.
H01S 5/20 - Structure or shape of the semiconductor body to guide the optical wave
G02B 6/10 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
H01S 5/0625 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
H01S 5/10 - Construction or shape of the optical resonator
H01S 5/12 - Construction or shape of the optical resonator the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
H01S 5/40 - Arrangement of two or more semiconductor lasers, not provided for in groups
B82Y 20/00 - Nanooptics, e.g. quantum optics or photonic crystals
H01S 5/343 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser
A method of characterizing a monolithic tunable mid-infrared laser including a heterogeneous quantum cascade active region together with a least first and a second tunable integrated distributed feedback gratings, the method including operating the laser while tuning the first grating through its full tuning range, while holding the reflectivity function of the second grating constant, then operating the laser while tuning the second grating through its full tuning range, while holding the reflectivity function of the first grating constant.
H01S 3/10 - Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
H01S 5/0687 - Stabilising the frequency of the laser
H01S 5/06 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
H01S 5/0625 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
H01S 5/12 - Construction or shape of the optical resonator the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
B82Y 20/00 - Nanooptics, e.g. quantum optics or photonic crystals
H01S 3/1055 - Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling the mutual position or the reflecting properties of the reflectors of the cavity one of the reflectors being constituted by a diffraction grating
o of the optical mode in the low loss waveguide between Na and Nb, wherein No is within a 5% error margin of identical to a refractive index of the gain section and wherein the gain section is butt-jointed with the low loss waveguide, and wherein the size and shape of the optical mode(s) in the low loss waveguide and gain section are within a 10% error margin of equal. Desirably, at least one of the semiconductor materials A and B has a sufficiently large band gap that the passive waveguide structure blocks current under a voltage bias of 15 V.
H01S 5/026 - Monolithically integrated components, e.g. waveguides, monitoring photo-detectors or drivers
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
H01S 5/02 - Structural details or components not essential to laser action
H01S 5/20 - Structure or shape of the semiconductor body to guide the optical wave
H01S 5/0625 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
13.
PASSIVE WAVEGUIDE STRUCTURE FOR OPTOELECTRONIC DEVICES
Disclosed is a semiconductor optical emitter having an optical mode and a gain section, the emitter comprising a low loss waveguide structure made of two alternating layers of semiconductor materials A and B, having refractive indexes of Na and Nb, respectively, with an effective index No of the optical mode in the low loss waveguide between Na and Nb, wherein No is within a 5% error margin of identical to a refractive index of the gain section and wherein the gain section is butt-jointed with the low loss waveguide, and wherein the size and shape of the optical mode(s) in the low loss waveguide and gain section are within a 10% error margin of equal. Desirably, at least one of the semiconductor materials A and B has a sufficiently large band gap that the passive waveguide structure blocks current under a voltage bias of 15 V.
A monolithic tunable mid-infrared laser has a wavelength range within the range of 3-14 μm and comprises a heterogeneous quantum cascade active region together with at least a first integrated grating. The heterogeneous quantum cascade active region comprises at least one stack, the stack comprising two, desirably at least three differing stages. Methods of operating and calibrating the laser are also disclosed.
H01S 3/10 - Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
H01S 5/06 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
H01S 5/0625 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
H01S 5/12 - Construction or shape of the optical resonator the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
B82Y 20/00 - Nanooptics, e.g. quantum optics or photonic crystals
H01S 3/1055 - Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling the mutual position or the reflecting properties of the reflectors of the cavity one of the reflectors being constituted by a diffraction grating
Disclosed is a method of forming a laser source capable of producing mid-IR laser radiation comprises growing a first core structure on a substrate, etching away the first core structure in one or more locations, and growing a second core structure on the substrate. At least one of the core structures comprises a quantum cascade gain medium emitting at a frequency within the range from 3-14 μm. Also disclosed is a laser source capable of producing mid-IR laser radiation comprising a quantum-cascade core positioned on a substrate for emitting within the range from 3-14 μm and a second core on the substrate positioned in-plane relative to the first core. The second core is one of a) a passive waveguide core b) a second quantum-cascade core and c) a semiconductor active core region.
H01S 3/10 - Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
B82Y 20/00 - Nanooptics, e.g. quantum optics or photonic crystals
H01S 5/343 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser
H01S 5/026 - Monolithically integrated components, e.g. waveguides, monitoring photo-detectors or drivers
o of the optical mode in the low loss waveguide between Na and Nb, wherein No is within a 5% error margin of identical to a refractive index of the gain section and wherein the gain section is butt-jointed with the low loss waveguide, and wherein the size and shape of the optical mode(s) in the low loss waveguide and gain section are within a 10% error margin of equal. Desirably, at least one of the semiconductor materials A and B has a sufficiently large band gap that the passive waveguide structure blocks current under a voltage bias of 15 V.
H01S 5/026 - Monolithically integrated components, e.g. waveguides, monitoring photo-detectors or drivers
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
H01S 5/02 - Structural details or components not essential to laser action
H01S 5/20 - Structure or shape of the semiconductor body to guide the optical wave
A semiconductor radiation source comprises an active core structure comprising a semiconductor material, at least one microheater positioned above the active core structure in thermal communication with the active core structure, and at least a first electrode positioned on a side of the microheater in electrical communication with the active core structure for injecting current into the active core structure to control the current density in the active core structure. Methods of operation of the source to provide tuning of the output wavelength are also disclosed.
A quantum cascade laser structure comprises a plurality of quantum wells and a plurality of barriers, at least a portion of which define an active region, one end of said active region being bordered by an injector barrier, wherein two or more adjacent quantum wells of the plurality in the plurality of quantum wells that define the active region are positioned next to the injector barrier and each of the two or more wells have a width narrower than the widths of two or more succeeding quantum wells in the plurality of quantum wells that define the active region. The resulting active region has increased lifetime of the transition from the upper to the lower photon emission energy state, resulting in higher efficiencies and better overall performance particularly for devices emitting or lasing at long wavelengths (> 7 μm).
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
19.
Mid-IR multiwavelength concatenated distributed-feedback laser with an active core made of cascaded stages
Concatenated distributed feedback lasers having multiple laser sections laid out in series are disclosed. The concatenated distributed feedback lasers utilize quantum cascade core designs to produce optical gain in the mid-infrared region and may generate several wavelengths simultaneously or sequentially. Methods of making along with methods of using such devices are also disclosed.
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
H01S 5/0625 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
H01S 5/10 - Construction or shape of the optical resonator
B82Y 20/00 - Nanooptics, e.g. quantum optics or photonic crystals
A monolithic tunable mid- infrared laser has a wavelength range within the range of 3- 14 μm and comprises a heterogeneous quantum cascade active region together with at least a first integrated grating. The heterogeneous quantum cascade active region comprises at least one stack, the stack comprising two, desirably at least three differing stages. Methods of operating and calibrating the laser are also disclosed.
H01S 5/0625 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
H01S 5/10 - Construction or shape of the optical resonator
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
H01S 5/40 - Arrangement of two or more semiconductor lasers, not provided for in groups
21.
MULTIWAVELENGTH QUANTUM CASCADE LASER VIA GROWTH OF DIFFERENT ACTIVE AND PASSIVE CORES
Disclosed is a method of forming a laser source capable of producing mid-IR laser radiation comprises growing a first core structure on a substrate, etching away the first core structure in one or more locations, and growing a second core structure on the substrate. At least one of the core structures comprises a quantum cascade gain medium emitting at a frequency within the range from 3-14 μm. Also disclosed is a laser source capable of producing mid-IR laser radiation comprising a quantum- cascade core positioned on a substrate for emitting within the range from 3-14 μm and a second core on the substrate positioned in-plane relative to the first core. The second core is one of a) a passive waveguide core b) a second quantum-cascade core and c) a semiconductor active core region.
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
H01S 5/40 - Arrangement of two or more semiconductor lasers, not provided for in groups
H01S 5/026 - Monolithically integrated components, e.g. waveguides, monitoring photo-detectors or drivers
Concatenated distributed feedback lasers having novel waveguides are disclosed. The waveguides allow for coupling of the laser beam between active and passive waveguide structures and improved device design and output efficiency. Methods of making along with methods of using such devices are also disclosed.
G02B 6/10 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
H01S 5/20 - Structure or shape of the semiconductor body to guide the optical wave
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
H01S 5/0625 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
H01S 5/10 - Construction or shape of the optical resonator
H01S 5/12 - Construction or shape of the optical resonator the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
H01S 5/40 - Arrangement of two or more semiconductor lasers, not provided for in groups
B82Y 20/00 - Nanooptics, e.g. quantum optics or photonic crystals
Multi-surface emitting mid-IR multiwavelength distributed-feedback quantum cascade ring lasers laid out in a concentric circle are disclosed. The lasers utilize quantum cascade core designs to produce optical gain in the mid-infrared region and may generate several wavelengths simultaneously or sequentially. Methods of making along with methods of using such devices are also disclosed.
H01S 5/32 - Structure or shape of the active regionMaterials used for the active region comprising PN junctions, e.g. hetero- or double- hetero-structures
H01S 5/40 - Arrangement of two or more semiconductor lasers, not provided for in groups
H01S 5/12 - Construction or shape of the optical resonator the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
H01S 5/187 - Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only horizontal cavities, e.g. horizontal cavity surface-emitting lasers [HCSEL] using Bragg reflection
H01S 5/22 - Structure or shape of the semiconductor body to guide the optical wave having a ridge or a stripe structure
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
Included are embodiments of a quantum cascade laser structure. Some embodiments include a plurality of quantum wells and a plurality of barriers, at least a portion of which define an active region. In some embodiments, a photon is emitted in the active region when an electron transitions from an upper laser state in the active region to a lower laser state in the active region. Additionally, a final quantum well in the plurality of quantum wells may define the active region, where the final quantum well extends below an adjacent quantum well in the active region. Similarly, the final quantum well may include a thickness that is less than a thickness of the adjacent quantum well in the active region.
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
B82Y 20/00 - Nanooptics, e.g. quantum optics or photonic crystals
25.
DBR laser diode with symmetric aperiodically shifted grating phase
A multi-wavelength distributed Bragg reflector (DBR) semiconductor laser is provided where DBR heating elements are positioned over the waveguide in the DBR section and define an interleaved temperature profile that generates multiple distinct reflection peaks corresponding to distinct temperature dependent Bragg wavelengths associated with the temperature profile. Neighboring pairs of heating elements of the DBR heating elements positioned over the waveguide in the DBR section are spaced along the direction of the axis of optical propagation by a distance that is equal to or greater than the laser chip thickness b to minimize the impact of thermal crosstalk between distinct temperature regions of the interleaved temperature profile.
A quantum cascade laser and its method of fabrication are provided. The quantum cascade laser comprises one or more p-type electrical isolation regions and a plurality of electrically isolated laser sections extending along a waveguide axis of the laser. An active waveguide core is sandwiched between upper and lower n-type cladding layers and the active core and the upper and lower n-type cladding layers extend through the electrically isolated laser sections of the quantum cascade laser. A portion of the upper n-type cladding layer comprises sufficient p-type dopant to have become p-type and to have become an electrical isolation region, which extends across at least a part of the thickness upper n-type cladding layer along a projection separating the sections of the quantum cascade laser.
A quantum cascade laser and its method of fabrication are provided. The quantum cascade laser comprises one or more p-type electrical isolation regions and a plurality of electrically isolated laser sections extending along a waveguide axis of the laser. An active waveguide core is sandwiched between upper and lower n-type cladding layers and the active core and the upper and lower n-type cladding layers extend through the electrically isolated laser sections of the quantum cascade laser. A portion of the upper n-type cladding layer comprises sufficient p-type dopant to have become p-type and to have become an electrical isolation region, which extends across at least a part of the thickness upper n-type cladding layer along a projection separating the sections of the quantum cascade laser. Laser structures are also contemplated where isolation regions are solely provided at the window facet sections of the laser to provide vertical isolation in the facet sections, to reduce the current into the facet regions of the laser, and help minimize potentially harmful facet heating.
H01S 5/34 - Structure or shape of the active regionMaterials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
B82Y 20/00 - Nanooptics, e.g. quantum optics or photonic crystals
H01S 5/0625 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium by varying the potential of the electrodes in multi-section lasers
H01S 5/16 - Window-type lasers, i.e. with a region of non-absorbing material between the active region and the reflecting surface
H01S 5/10 - Construction or shape of the optical resonator
H01S 5/22 - Structure or shape of the semiconductor body to guide the optical wave having a ridge or a stripe structure
A semiconductor optical amplifier (SOA) with efficient current injection is described. Injection current density is controlled to be higher in some areas and lower in others to provide, e.g., improved saturation power and/or noise figure. Controlled injection current can be accomplished by varying the resistivity of the current injection electrode. This, in turn, can be accomplished by patterning openings in the dielectric layer above the current injection metallization in a manner which varies the series resistance along the length of the device.
A semiconductor laser device operable to emit light having a desired wavelength in the green spectral range. The semiconductor laser device may include a pumping source and a laser structure including a substrate, a first cladding layer, and one or more active region layers. The one or more active region layers include a number of quantum wells having a spontaneous emission peak wavelength that is greater than about 520 nm at a reference pumping power density. The pumping source is configured to pump each quantum well at a pumping power density such that a stimulated emission peak of each quantum well is within the green spectral range, and the number of quantum wells within the one or more active region layers is such that a net optical gain of the quantum wells is greater than a net optical loss coefficient at the desired wavelength in the green spectral range.
A method and system for generating an optical frequency comb that employs a dual parallel modulator that inputs an optical signal at a center frequency of a desired optical frequency comb and an RF signal at a frequency corresponding to a desired spacing of the teeth of the optical frequency comb. The amplitudes of the teeth of the optical frequency comb are controlled by controlling the amplitudes of the two RF inputs to the DPM and the phase shift between the two RF inputs. In some embodiments, the three bias voltages for the three interferometers in the DPM are also controlled. In some embodiments, all three interferometers are all biased at the same point (e.g., quadrature). Preferably, but not necessarily, the three interferometers of the DPM are formed on a single substrate.
G02F 1/035 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels or Kerr effect in an optical waveguide structure
32.
Fracture resistant metallization pattern for semiconductor lasers
Metallization patterns are provided to reduce the probability of chip fracture in semiconductor lasers. According to one embodiment disclosed herein, the pad edges of a metallization pattern extend across a plurality of crystallographic planes in the laser substrate. In this manner, cracks initiated at any given stress concentration would need to propagate across many crystallographic planes in the substrate to reach a significant size. Additional embodiments of the present disclosure relate to the respective geometries and orientations of adjacent pairs of contact pads. Still further embodiments are disclosed and claimed.
A method is provided for controlling a DBR laser diode wherein front and rear DBR section heating elements are controlled such that the reflectivity of the rear grating portion of the DBR section is lower than the reflectivity of the front grating portion of the DBR section. In this manner, lasing mode selection is dominated by the front grating portion and the front DBR section heating element can be controlled for wavelength tuning. In addition, the rear DBR section heating element can be controlled to narrow the spectral bandwidth of the DBR reflection spectra. Additional embodiments are disclosed and claimed.
Methods for forming grating profiles in semiconductor laser structures comprise the steps of providing a semiconductor wafer comprising a wafer substrate, an etch stop layer disposed over the wafer substrate, a grating layer disposed over the etch stop layer, an etch mask layer disposed over the grating layer, and a photoresist layer disposed over the etch mask layer, forming a photoresist grating pattern, transferring the photoresist grating pattern into the grating layers via dry etching, and removing the photoresist layer, selectively wet etching the grating layer to form the grating profile in the grating layer. The placement of the grating layer between the etch mask and etch stop layers controls the selective wet etching step. The method also comprises removing the etch mask layer via selective wet etching without altering the grating profile, and regrowing an upper cladding layer to produce the semiconductor laser structure.
A semiconductor laser source is provided wherein the wavelength selective section of the laser diode comprises a P+ type current confinement layer and first and second sets of interdigital heater electrodes formed over the current confinement layer. Individual electrode digits of the first and second sets of interdigital heater electrodes alternate in succession along a direction of optical propagation defined by the active waveguide layer of the laser diode. The first set of interdigital heater electrodes are positively or negatively biased relative to the laser diode cathode and relative to the second set of interdigital heater electrodes such that the relative bias is either less than the forward bias turn-on voltage of the P-N junction or has an absolute value less than the reverse break-down voltage of the P-N junction.
Embodiments of a method of quantum well intermixing (QWI) comprise providing a wafer comprising upper and lower epitaxial layers, which each include barrier layers, and a quantum well layer disposed between the upper and lower epitaxial layers, applying at least one sacrificial layer over the upper epitaxial layer, and forming a QWI enhanced region and a QWI suppressed region by applying a QWI enhancing layer over a portion of the sacrificial layer, wherein the portion under the QWI enhancing layer is the QWI enhanced region, and the other portion is the QWI suppressed region. The method further comprises the steps of applying a QWI suppressing layer over the QWI enhanced region and the QWI suppressed region, and annealing at a temperature sufficient to cause interdiffusion of atoms between the quantum well layer and the barrier layers of the upper epitaxial layer and the lower epitaxial layer.
A semiconductor optical amplifier (SOA) with efficient current injection is described. Injection current density is controlled to be higher in some areas and lower in others to provide, e.g., improved saturation power and/or noise figure. Controlled injection current can be accomplished by varying the resistivity of the current injection electrode. This, in turn, can be accomplished by patterning openings in the dielectric layer above the current injection metallization in a manner which varies the series resistance along the length of the device.
A semiconductor optical amplifier (SOA) with efficient current injection is described. Injection current density is controlled to be higher in some areas and lower in others to provide, e.g., improved saturation power and/or noise figure. Controlled injection current can be accomplished by varying the resistivity of the current injection electrode. This, in turn, can be accomplished by patterning openings in the dielectric layer above the current injection metallization in a manner which varies the series resistance along the length of the device.
09 - Scientific and electric apparatus and instruments
Goods & Services
OPTICAL AND OPTOELECTRICAL COMPONENTS, NAMELY, AMPLIFIERS FOR SINGLE AND MULTI-CHANNEL OPTICAL TELECOMMUNICATION AMPLIFICATION; MODULATORS FOR USE IN HIGH-SPEED FIBER OPTIC TELECOMMUNICATION AND CABLE-TELEVISION SYSTEMS; SEMICONDUCTOR LASERS; AND BROADBAND SUPERLUMINESCENT LIGHT EMITTING DIODES
