A multicore fiber (MCF) optical attenuator (MCF-ATT) can be configured to attenuate light traveling from at least one core of a first MCF to at least one core of a second MCF at least at one wavelength W−1. The MCF-ATT can include a plurality of optical waveguides and an attenuating section within the plurality of optical waveguides. The attenuating section can include a distorted portion of the plurality of optical waveguides. The distorted portion can be configured to couple at least one propagating optical mode with at least one radiation mode at the wavelength W−1.
A multicore fiber (MCF) optical attenuator (MCF-ATT) can be configured to attenuate light traveling from at least one core of a first MCF to at least one core of a second MCF at least at one wavelength W-1. The MCF-ATT can include a plurality of optical waveguides and an attenuating section within the plurality of optical waveguides. The attenuating section can include a distorted portion of the plurality of optical waveguides. The distorted portion can be configured to couple at least one propagating optical mode with at least one radiation mode at the wavelength W-1.
A multichannel optical coupler array can include a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides can be a vanishing core waveguide having an inner vanishing core having a first refractive index (N-1), an outer core having a second refractive index (N-2), and an outer cladding having a third refractive index (N-3). A refractive index transition between N-1 and N-2 can have a function form N(r), where r is a transverse distance from the inner vanishing core center. The function N(r) can be a smooth function having a positive average of the second derivative or function N(r) can be a step function with at least one step approximating the smooth function. The coupler housing structure may have non-circular holes formed by convex-shaped housing structure elements.
Wavelength division multiplexers for space division multiplexing can include wavelength division multiplexing fanout devices or pump-signal combiners for multicore fibers. The disclosure can include wavelength division multiplexers for space division multiplexing (SDM-WDM devices), including wavelength division multiplexing fanout devices and pump-signal combiners for MCFs. The disclosure can include space division multiplexers (SDMs), including adapters between MCFs with different core patterns and/or add-drop multiplexers for MCFs.
Wavelength division multiplexers for space division multiplexing can include wavelength division multiplexing fanout devices or pump-signal combiners for multicore fibers.
A multichannel optical coupler array can include a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides can be a vanishing core waveguide having an inner vanishing core having a first refractive index (N-1), an outer core having a second refractive index (N-2), and an outer cladding having a third refractive index (N-3). A refractive index transition between N-1 and N-2 can have a function form N(r), where r is a transverse distance from the inner vanishing core center. The function N(r) can be a smooth function having a positive average of the second derivative or function N(r) can be a step function with at least one step approximating the smooth function. The coupler housing structure may have non-circular holes formed by convex-shaped housing structure elements.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
G02B 6/30 - Optical coupling means for use between fibre and thin-film device
A multichannel optical coupler array can include a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides can be a vanishing core waveguide having an inner vanishing core having a first refractive index (N-1), an outer core having a second refractive index (N-2), and an outer cladding having a third refractive index (N-3). A refractive index transition between N-1 and N-2 can have a function form N(r), where r is a transverse distance from the inner vanishing core center. The function N(r) can be a smooth function having a positive average of the second derivative or function N(r) can be a step function with at least one step approximating the smooth function. The coupler housing structure may have non-circular holes formed by convex-shaped housing structure elements.
Space division multiplexers can include adapters between multicore fibers with different core patterns and/or add-drop multiplexers for multicore fibers.
The optical fiber coupler array can be capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array can be configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. Advantageously, the refractive indices and sizes of both inner and outer core, and/or other characteristics of vanishing core waveguides in the optical coupler array can be configured to reduce the back reflection for light propagating from the plurality of the optical fibers at the coupler first end to the optical device at the coupler second end, and/or vice versa.
An optical fiber connector configured to rotationally align a first optical fiber with a second optical fiber is provided. The connector can include at least two rotational alignment features. At least one of the two rotational alignment features can include at least one ferrule configured to hold at least the first optical fiber.
An optical coupler array can include an elongated optical element having a coupler housing structure and at least one longitudinal waveguide embedded in said housing structure. The housing structure can have an outer cross sectional shape comprising a first side comprising one or more curved portions and a second side comprising one or more flat portions. The second side can be disposed at a distance from the at least one longitudinal waveguide such that waveguiding properties are preserved and not disturbed.
A multichannel optical coupler can include an output optical coupler array and a plurality of optical fibers. At least two of the plurality of optical fibers can be connected together at an end opposite the output optical coupler array.
The optical fiber coupler array can be capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array can be configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. Advantageously, the refractive indices and sizes of both inner and outer core, and/or other characteristics of vanishing core waveguides in the optical coupler array can be configured to reduce the back reflection for light propagating from the plurality of the optical fibers at the coupler first end to the optical device at the coupler second end, and/or vice versa.
G02B 6/12 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
An optical coupler array can include an elongated optical element having a coupler housing structure and at least one longitudinal waveguide embedded in said housing structure. The housing structure can have an outer cross sectional shape comprising a first side comprising one or more curved portions and a second side comprising one or more flat portions. The second side can be disposed at a distance from the at least one longitudinal waveguide such that waveguiding properties are preserved and not disturbed.
Advantageously, at least one embodiment of the present disclosure comprises a polarization maintaining PROFA (“PM-PROFA”) coupler in which the polarization axes of the individual vanishing core waveguides thereof are oriented or aligned without the need to adjust the orientation of each individual VC waveguide.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
G02B 6/024 - Optical fibres with cladding with polarisation-maintaining properties
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
An optical coupler array can include an elongated optical element having a coupler housing structure and at least one longitudinal waveguide embedded in said housing structure. The housing structure can have an outer cross sectional shape comprising a first side comprising one or more curved portions and a second side comprising one or more flat portions. The second side can be disposed at a distance from the at least one longitudinal waveguide such that waveguiding properties are preserved and not disturbed.
A multichannel optical coupler can include an output optical coupler array and a plurality of optical fibers. At least two of the plurality of optical fibers can be connected together at an end opposite the output optical coupler array.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
An optical coupler array comprises a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides is a vanishing core waveguide. Light traveling from a first end to a second end can escape from an inner vanishing core into a corresponding outer core proximally to an intermediate cross section, and can escape from the outer core into a combined waveguide formed by at least two neighboring outer cores proximally to the second end.
A multichannel optical coupler array comprises a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides is a vanishing core waveguide. Light traveling from a first end to a second end can escape from an inner vanishing core into a corresponding outer core proximally to an intermediate cross section, and can escape from the outer core into a combined waveguide formed by at least two neighboring outer cores proximally to the second end.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
G02B 6/30 - Optical coupling means for use between fibre and thin-film device
G02B 6/028 - Optical fibres with cladding with core or cladding having graded refractive index
A multichannel optical coupler array comprises a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides is a vanishing core waveguide. The coupler housing structure at a proximity to a first end has one of the following cross sectional configurations: a ring surrounding the longitudinal waveguides, or a structure with holes, at least one hole containing at least one of the longitudinal waveguides.
The inventive high density optical packaging header apparatus, in various embodiments thereof, provides configurable, modular, and highly versatile solutions for simultaneously connecting multiple optical fibers/waveguides to optical-fiber-based electronic systems, components, and devices, and is readily usable in a variety of applications involving highly flexible and modular connection of multiple optical fibers/waveguides assembled in a header block configuration to optical-fiber-based system/component backplanes, while providing advantageous active and passive alignment features.
The present invention provides an optical in-fiber chiral fiber isolator, capable of transmitting a signal of a predetermined optical polarization in a forward direction therethrough, while rejecting all signals traveling in a backward direction therethrough, and a method of fabrication thereof. In one exemplary embodiment, the inventive optical chiral fiber isolator includes a chiral magneto-optical fiber having a helical pitch profile, a birefringence profile, and an effective Verdet constant profile, at least a portion of which is exposed to a magnetic field of a predetermined magnetic field profile (generated by a proximal magnetic field source), where the magnetic field profile, the chiral pitch profile, the birefringence profile, and the effective Verdet constant profile are selected and configured such that the inventive isolator is capable of transmitting a signal of a predetermined optical polarization in a direction from its input end toward its output end, and to reject all signals in a direction from its output end to its input end.
G02F 1/095 - 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 magneto-optical elements, e.g. exhibiting Faraday effect in an optical waveguide structure
The present disclosure provides a pitch reducing optical fiber array or a multicore fiber including at least one chiral fiber grating incorporated therein that is operable to couple the modes in different fiber cores within a spectral range determined in some instances by the helical pitch of the corresponding chiral fiber grating.
G02B 6/10 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
G02B 6/44 - Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
The inventive configurable optical fiber polarization mode coupler is capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing, and that are preferably optimized for use with photonic integrated circuits, such as coupling to dense optical input/output interfaces, wafer-level testing, etc. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Advantageously, in at least one embodiment of the present invention, the configurable optical fiber polarization mode coupler addresses various polarization-related applications.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
G02B 6/024 - Optical fibres with cladding with polarisation-maintaining properties
G02B 6/30 - Optical coupling means for use between fibre and thin-film device
G02B 6/00 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings
The inventive configurable chiral fiber sensor with a tip-positioned sensing element, is readily configurable for use in a variety of applications (such as applications involving pressure, temperature, and even axial twist sensing), and is particularly suitable for applications requiring highly precise and accurate sensor readings within corresponding predefined limited sensing ranges. Advantageously, the inventive configurable chiral fiber sensor with a tip-positioned sensing element, is operable to utilize a wide variety of light sources, photodetectors, and related devices for sensor interrogation.
G01K 11/32 - Measuring temperature based on physical or chemical changes not covered by group , , , or using changes in transmittance, scattering or luminescence in optical fibres
The present invention is directed to an optical fiber grating having a core, that is capable of controlling the light signal transmission therethrough by causing at least one of: at least one spectral peak, and/or at least one spectral dip in its core light transmission spectrum, corresponding to at least one predetermined wavelength. The inventive optical fiber diffraction grating comprises at least one longitudinally positioned structural element of a predetermined geometric profile and that is configured for diffracting a portion of the transmitted light signal at at least one predefined wavelength thereof, from at least one core mode into at least one of: at least one cladding mode and/or at least one radiating mode. Various embodiments of a number of novel techniques for fabrication of the inventive optical fiber diffraction grating are provided, inclusive of a novel technique for fabricating the inventive grating from a single material. Advantageously, such novel fabrication techniques rely on configuration of a desired geometric profile for the at least one structural element portion of the novel grating, each profile comprising a number of readily configurable parameters that can be selected and/or adjusted during fabrication, to produce a variety of novel fiber diffraction gratings, each having a corresponding specific desirable core transmission spectrum having at least one of: least one spectral peak, and/or at least one spectral dip therein, corresponding to at least one specific desired wavelength, dependent on the configuration of the applicable geometric profile.
The system and method of the present invention advantageously enable controllable light extraction from optical fiber waveguides and offer highly configurable light signal guidance and control capabilities, as well as additional advantageous features associated with waveguides, by providing, in various exemplary embodiments thereof, a multitude of novel techniques by which the parameters relating to utilization of various light signals (such as direction of their emission, magnitude of the emission, physical surface area of the emission, etc.), can be readily controlled and configured as a matter of design choice. Additionally, the inventive system and method, in various exemplary embodiments thereof, also enable and facilitate selective configuration of, and/or control over, various characteristics of the light signals guided/controlled/extracted thereby, such as the signals' wavelength, polarization, intensity, amplitude, etc. To achieve the above-noted beneficial functions, the system and method of the present invention utilize a physical property of a standard, or a specialty, chiral optical fiber to scatter light signals entering the fiber in directions away from the fiber core (through the fiber cladding), to thereby advantageously enable selective and controllable extraction of light signals of a desired predetermined wavelength (or, optionally of a predetermined range of wavelengths) therefrom.
G02B 6/00 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings
F21V 8/00 - Use of light guides, e.g. fibre optic devices, in lighting devices or systems
F21K 9/61 - Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction using light guides
F21K 9/232 - Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
Advantageously, at least one embodiment comprises a flexible pitch reducing optical fiber array (PROFA) coupler capable of maintaining all channels discretely with sufficiently low crosstalk, while providing enough flexibility to accommodate low profile packaging, and having increased stability with respect to environmental fluctuations, including temperature variations and mechanical shock and vibration, and that is combinable in multiple quantities thereof to form an optical multi-port input/output (IO) interface.
G02B 6/12 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
G02B 6/30 - Optical coupling means for use between fibre and thin-film device
Advantageously, at least one embodiment of the present disclosure comprises a polarization maintaining PROFA (“PM-PROFA”) coupler in which the polarization axes of the individual vanishing core waveguides thereof are oriented or aligned without the need to adjust the orientation of each individual VC waveguide.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
G02B 6/024 - Optical fibres with cladding with polarisation-maintaining properties
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
The inventive configurable optical fiber polarization mode coupler is capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing, and that are preferably optimized for use with photonic integrated circuits, such as coupling to dense optical input/output interfaces, wafer-level testing, etc. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Advantageously, at least one embodiment of the present invention comprises a phase locking optical fiber coupler comprising at least one optical fiber coupler configured as a pitch reducing optical fiber array (PROFA) component configured and optimized coherent combining of multiple optical fiber lasers to produce multi-kilowatt single mode laser sources.
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
A multichannel optical coupler array comprises a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides is a vanishing core waveguide. The coupler housing structure at a proximity to a first end has one of the following cross sectional configurations: a ring surrounding the longitudinal waveguides, or a structure with holes, at least one hole containing at least one of the longitudinal waveguides.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
G02B 6/30 - Optical coupling means for use between fibre and thin-film device
G02B 6/024 - Optical fibres with cladding with polarisation-maintaining properties
Advantageously, at least one embodiment of the present disclosure comprises a polarization maintaining PROFA ("PM-PROFA") coupler in which the polarization axes of the individual vanishing core waveguides thereof are oriented or aligned without the need to adjust the orientation of each individual VC waveguide.
G02B 6/024 - Optical fibres with cladding with polarisation-maintaining properties
G02B 6/028 - Optical fibres with cladding with core or cladding having graded refractive index
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
The inventive configurable optical fiber polarization mode coupler is capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing, and that are preferably optimized for use with photonic integrated circuits, such as coupling to dense optical input/output interfaces, wafer-level testing, etc. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Advantageously, at least one embodiment of the present invention comprises a physically untappable secure optical fiber link component comprising at least one optical fiber polarization mode coupler configured as a pitch reducing optical fiber array (PROFA) interconnect.
Advantageously, at least one embodiment comprises a flexible pitch reducing optical fiber array (PROFA) coupler capable of maintaining all channels discretely with sufficiently low crosstalk, while providing enough flexibility to accommodate low profile packaging, and having increased stability with respect to environmental fluctuations, including temperature variations and mechanical shock and vibration, and that is combinable in multiple quantities thereof to form an optical multi-port input/output (10) interface.
G02B 6/12 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
The inventive optical fiber coupler array is capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Alternatively, the novel coupler array may be configured for utilization with at least one of an optical fiber amplifier and an optical fiber laser. Advantageously, the refractive indices and sizes of both inner and outer core, and/or other characteristics of vanishing core waveguides in the novel optical coupler array are optimized to reduce the back reflection for light propagating from the plurality of the optical fibers at the coupler first end to the optical device at the coupler second end, and/or vice versa.
G02B 6/30 - Optical coupling means for use between fibre and thin-film device
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
The inventive optical fiber coupler array is capable of providing a low- loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel -to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Alternatively, the novel coupler array may be configured for utilization with at least one of an optical fiber amplifier and an optical fiber laser.
The inventive optical component assembly advantageously enables a multi-waveguide optical component (such as the inventive optical fiber coupler array, a multi-core optical fiber, etc.), to be coupled to at least one waveguide of an optical device at a predefined coupling angle. The optical component assembly of the present invention comprises a multi-waveguide optical component with an output end, a prism having an input surface, an output surface, and an internal reflective surface with a predefined reflection angle, and a GRIN lens, positioned between the component output end and the prism input surface, along a longitudinal axis of the multi-waveguide optical component. In accordance with the present invention, the length of the GRIN lens, and its refractive index gradient profile are optimized to form an optical image of the output end of the multi-waveguide optical component, at the output surface of the prism, thus enabling the output surface of the prism to be coupled to at least one waveguide of an optical device, with the predefined reflection angle corresponding to the angle at which the multi-waveguide optical component may be coupled to the optical device.
G02B 6/28 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
G02B 6/30 - Optical coupling means for use between fibre and thin-film device
The inventive optical fiber coupler array is capable of providing a low loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. The novel optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core fiber, at least in part embedded within a common housing structure. Alternatively, the novel coupler array may be configured for utilization with at least one of an optical fiber amplifier and an optical fiber laser.
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
The inventive circular chiral fiber polarizer is operable to convert linearly polarized light to circularly polarized light, may be advantageously fabricated in an “in-fiber” manner and to comprise desirable extinction ratio characteristics, and may also serve as an interface between a sequentially positioned polarization maintaining (PM) fiber, and a single mode (SM) fiber.
G02B 6/00 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings
G02B 6/27 - Optical coupling means with polarisation selective and adjusting means
G02B 6/024 - Optical fibres with cladding with polarisation-maintaining properties
G02B 6/10 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
The inventive chiral polarization preserving optical fiber utilizes a structure composed of specially positioned and configured single mode (SM) and conventional polarization maintaining (PM) fiber elements along with at least two novel circular chiral fiber polarizers (each operable to convert linearly polarized light to circularly polarized light), to preserve any arbitrary polarization state of light signals transmitted therethrough without the limitations and drawbacks of other polarization maintaining solutions. In another inventive embodiment thereof, the inventive chiral polarization preserving optical fiber is configured as an arbitrary polarization state maintaining light signal splitter.
A novel in-fiber polarizer is provided that is implemented in an optical fiber structure based on a polarization maintaining (“PM”) optical fiber, and that is configured to impart a predetermined desired polarization to a light signal transmission of a predetermined at least one wavelength transmitted therethrough. The inventive polarizer comprises a PM optical fiber structure, with an entry end for receiving incident light and an exit end for outputting polarized light, having an optical fiber core, having at least one core mode and a core propagation constant, surrounded by a cladding, having at least one cladding mode and a cladding propagation constant, that further comprises a reduced core diameter region of a predetermined length between its entry and exit ends, wherein various predefined parameters of the modified PM optical fiber structure, including but not being limited to, the core and cladding propagation constants, the value of the reduced core diameter, and the length of the reduced core diameter region are selected and configured to produce a constructive interference for one light polarization of the input light signal, corresponding to the desired polarization, and to produce a destructive interference for a polarization orthogonal to the desired polarization, to thereby only output, at the polarizer exit end, the desired polarization component of the light signal transmission at the at least one wavelength. Additional embodiments of the inventive polarizer include multiple sequential polarizer structures with specially configured interconnects.
The present invention is directed to an optical fiber grating having a core, that is capable of controlling the light signal transmission therethrough by causing at least one of: at least one spectral peak, and/or at least one spectral dip in its core light transmission spectrum, corresponding to at least one predetermined wavelength. The inventive optical fiber diffraction grating comprises at least one longitudinally positioned structural element of a predetermined geometric profile and that is configured for diffracting a portion of the transmitted light signal at at least one predefined wavelength thereof, from at least one core mode into at least one of: at least one cladding mode and/or at least one radiating mode. Various embodiments of a number of novel techniques for fabrication of the inventive optical fiber diffraction grating are provided, inclusive of a novel technique for fabricating the inventive grating from a single material. Advantageously, such novel fabrication techniques rely on configuration of a desired geometric profile for the at least one structural element portion of the novel grating, each profile comprising a number of readily configurable parameters that can be selected and/or adjusted during fabrication, to produce a variety of novel fiber diffraction gratings, each having a corresponding specific desirable core transmission spectrum having at least one of: least one spectral peak, and/or at least one spectral dip therein, corresponding to at least one specific desired wavelength, dependent on the configuration of the applicable geometric profile.
A chiral optical fiber polarizer is provided that is capable of being fabricated in-line along a conventional polarization maintaining fiber, preferably one which includes at least one structure element that is external, and parallel, to the fiber's core. The novel chiral fiber polarizer is preferably positioned between two unmodified optical fiber portions, and includes a modified central portion with altered fiber cladding interface elements on each side thereof. The modified central portion is of a non-circuiar cross section, and comprises at least one diameter reduced sub-section operable to allow a light signal of said predefined operation wavelength to propagate substantially in the core and in the at least one external structure element, at least one diameter expanded sub-section operable to allow a light signal to propagate substantially in the core, each sub-section being produced in accordance with a corresponding predefined diameter reduction and expansion profile, where the modified central portion is further configured in accordance with at least one helical pitch profile that is operable to, upon receiving a light signal with a first and second linear polarization components: convert the first linear polarization component to a first elliptical polarization component white scattering the first elliptical polarization component, and convert the second linear polarization component to a second elliptical polarization component, transmit therethrough, and convert back to the second linear polarization component prior to exit therefrom. The inventive polarizer also substantially eliminates the possibility of an undesirable SBS effect.
An optical fiber coupler array capable of providing multiple low loss, high coupling coefficient interfaces between a predetermined number of low numerical aperture optical fibers and an optical waveguide device with at least a corresponding number of waveguide interfaces. The novel coupler array includes a plurality of coupler inner cores and a plurality of corresponding coupler outer cores, within a medium surrounding each plural outer core, and also includes a first end for interfacing with plural optical fibers and a second enό for interfacing with a plurality of waveguide interfaces of an optical waveguide device. The sizes of the inner and outer cores are gradually reduced from the first end to the second end in accordance with at least one predetermined reduction profile. Various parameters, such as refractive indices and sizes of the inner and outer cores and the medium (as well as the reduction profile) are selected to produce a plurality of low numerical aperture waveguides at the first end, and a plurality of high numerical aperture waveguides at the second end, while advantageously minimizing insertion loss and maximizing the coupling coefficient at each end. Advantageously, the novel coupler array may be fabricated as an array of individually drawn couplers from multiple parallel fused performs (arranged in a row, or in another geometric cross section). Alternately, the novel coupler array may be fabricated from a single perform (glass or polymer) embedded with a plurality of parallel inner and outer core sets.
A single helix chiral fiber grating of a predetermined grating strength is provided that is operable to control light transmission in a predetermined wavelength range. The novel fiber grating comprises a first optical fiber with a first interface portion at a first end, a second interface portion at a second end, and a middle portion therebetween. The first optica! fiber is configured with at least one fiber core, surrounded by a corresponding at least one cladding, with a first longitudinal section disposed within the first interface portion, a second longitudinal section disposed within the second interface portion, and also includes a longitudinal helical section, disposed therebetween within the middle portion, that comprises a longitudinal helix structure of a single predetermined handedness, having a predetermined pitch profile, and having a predetermined helix diameter profile selected and configured to produce the predetermined grating strength. The helical section of the novel fiber grating is preferably produced by placing the first optical fiber, proximal to and parallel with a second fiber (or equivalent elongated member), and longitudinally twisting them together to form a double helix structure. Advantageously, the diameter of the second fiber (or a diameter profile thereof) may be selected to achieve the predetermined helix diameter profile in the helical section of the first fiber. The second fiber may be left proximal to the first fiber after fabrication or removed.
A chiral optical fiber polarizer is provided that is capable of being fabricated in-line along a conventional polarization maintaining fiber having external structural element(s), positioned between two optical fiber portions, and includes a modified central portion with altered fiber cladding interface elements on each side thereof. The modified central portion includes at least one diameter reduced sub-section that allows a light signal to propagate simultaneously in the core and in at least one external structure element, and at least one diameter expanded sub-section that allows the light signal to propagate substantially in the core, where the modified central portion is configured to be operable to serve as a polarizer for light signals with linear polarization components.
An optical fiber coupler array capable of providing multiple low loss, high coupling coefficient interfaces between a predetermined number of low numerical aperture optical fibers and an optical waveguide device with at least a corresponding number of waveguide interfaces. The novel coupler array includes a plurality of coupler inner cores and a plurality of corresponding coupler outer cores, within a medium surrounding each plural outer core, and also includes a first end for interfacing with plural optical fibers and a second end for interfacing with a plurality of waveguide interfaces of an optical waveguide device. The sizes of the inner and outer cores are gradually reduced from the first end to the second end in accordance with at least one predetermined reduction profile. Various parameters, such as refractive indices and sizes of the inner and outer cores and the medium (as well as the reduction profile) are selected to produce a plurality of low numerical aperture waveguides at the first end, and a plurality of high numerical aperture waveguides at the second end, while advantageously minimizing insertion loss and maximizing the coupling coefficient at each end. Advantageously, the novel coupler array may be fabricated as an array of individually drawn couplers from multiple parallel fused performs (arranged in a row, or in another geometric cross section). Alternately, the novel coupler array may be fabricated from a single perform (glass or polymer) embedded with a plurality of parallel inner and outer core sets.
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
A distributed elongated optica! fiber detection system is provided, having at least one sensitive region, and being capable of detecting the occurrence and locations) of one or more events along its length that cause one or more perturbations in the at least one sensitive region, in one embodiment of the invention, the novel detection system includes, at its first end, an optica! signal source capable of launching a signal in a first signal mode through an optica! fiber waveguide comprising at least one sensitive region along its length, and configured for transmitting at least two signal modes therethrough, toward its second end, A refiecting device, capable of reflecting only signals in a second signs! mode, is positioned at the second end of the waveguide. An occurrence of at ieast one event in at least one sensitive region causes a perturbation in the waveguide sufficient to couple at least a portion of the energy of the forward traveling signal into a second signal mode, such that the signal in the second signal mode is reflected back toward the first end of the waveguide. A detector, capable of detecting at least one characteristic of a reflected signal in the second signal mode, is connected to the first end of the waveguide, such that when the at ieast one event occurs, and a reflected signal in the second signal mode is produced, the detector is capable of determining the quantity of one or more occurring events as well as a location of each of the events along the waveguide lengths, in another inventive embodiment, instead of a reflector, the detector is connected to the second end and detects the signai in the second mode directly.
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G01M 3/08 - Investigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point by observing bubbles in a liquid pool for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point by observing bubbles in a liquid pool for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point by observing bubbles in a liquid pool for valves
G01M 3/38 - Investigating fluid tightness of structures by using light
49.
OPTICAL CHIRAL FIBER ISOLATOR AND METHOD OF FABRICATION THEREOF
The present invention provides an optical in-fiber chiral fiber isolator, capable of transmitting a signal of a predetermined optical polarization in a forward direction therethrough, while rejecting all signals traveling in a backward direction therethrough, and a method of fabrication thereof. In one exemplary embodiment, the inventive optical chiral fiber isolator includes a chiral magneto-optical fiber having a helical pitch profile, a birefringence profile, and an effective Verdet constant profile, at least a portion of which is exposed to a magnetic field of a predetermined magnetic field profile (generated by a proximal magnetic field source), where the magnetic field profile, the chiral pitch profile, the birefringence profile, and the effective Verdet constant profile are selected and configured such that the inventive isolator is capable of transmitting a signal of a predetermined optical polarization in a direction from its input end toward its output end, and to reject all signals in a direction from its output end to its input end.
An optical fiber mode coupling device, capable of being readily connected to a conventional optical fiber with a high degree of ruggedness, is provided. The inventive mode coupling device only allows transmission of at least one supported fiber mode therethrough, and is preferably configured to maximize the coupling, of at least one desired fiber mode, to the at least one supported fiber mode. Advantageously, the inventive mode coupling device is capable of performing the functions of a mode filter for the signal entering its first end, or serving as a mode conditioner for the signal entering its opposite second end. Thus, in one practical application thereof, the novel mode coupling device functions as a mode filter by maximizing the coupling between at least one desired fiber mode of a multi-mode input signal entering the device's first end, and at least one supported mode of the device, to produce an output signal at the device's second end that comprises at least one predetermined fiber mode, corresponding to at least one desired fiber mode. In another practical application thereof, the novel mode coupling device functions as a mode conditioner by maximizing the coupling between an input signal, comprising at least one predetermined fiber mode, that enters the device's second end, and, and at least one supported mode of the device, to produce an output signal at the device's first end that comprises at least one desired fiber mode, corresponding to a conditioned at least one predetermined fiber mode.
A chiral fiber grating, for reflecting, scattering or polarizing an optical signal, or for forming a fiber Saser feedback structure, comprises a chiral fiber having a singie heiix structure aiorsg its central longitudinal axis having a pitch equal to its period. The single heiix structure is achieved by ensuring that a chiral fiber is asymmetrical about its centra! longitudinal axis prior to twisting the fiber to produce the single helix chiral fiber grating, in an alternate embodiment of the present invention, a hybrid single heiix structure with certain double-helix properties may be produced by utilizing a fiber preform that has a 180 degree symmetrical core, that is asymmetrically offset from the preterm's longitudinal axis. Such a hybrid chiral fiber grating has a spectral response profile that includes, over certain waveSengths of Sight, spectral regions of polarization insensitivity, as well as spectra! regions of polarization sensitivity.
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