Abstract: An optical waveguide adapter assembly comprises a solid core optical waveguide extending between a free end and a coupled end and having a solid waveguiding core with an associated first optical mode field size; a hollow core optical waveguide extending between a free end and a coupled end and having a hollow waveguiding core with an associated second optical mode field size; and an optical mode field adapter extending between a first end and a second end and having a waveguiding core configured to change an optical mode field of a waveguided optical signal substantially between the first optical mode field size at the first end of the optical mode field adapter and the second optical mode field size at the second end of the optical mode field adapter, the first end of the optical mode field adapter joined to the coupled end of the solid core optical waveguide to provide optical coupling between the waveguiding core of the solid core optical waveguide and the waveguiding core of the optical mode field adapter

Abstract: Configurations for an optical splitter are disclosed. The optical splitter may include an input waveguide, a free propagation region, and an array of output waveguides. The input waveguide may be sufficiently narrow that the light in the free propagation region may diffract and provide the same optical intensity at far field angles across a wide wavelength range. The input waveguide may have a high V number in a vertical dimension and a low V number in a horizontal dimension. Because all of the wavelengths of light diffract at the same angle in the free propagation region, once the light reaches the output waveguides, the light may have similar optical power at each of the output waveguides. Additionally, the output waveguides may vary in width and spacing to mitigate the non-uniform optical power distribution of the phase front of light.

Abstract: A fibre optic cable structure (300) suitable for fibre optic sensing with an improved sensitivity to an environmental parameter is described. The structure (300) includes an optical fibre (301) and a bend inducer (304) responsive to the environmental parameter to control bending of the optical fibre. The bend inducer (304) is configured to adopt a first configuration, that induces a first curvature of the optical fibre, at a first value of the environmental parameter and to adopt a second configuration at a second, different, value of the environmental parameter that induces a second, different, curvature of the optical fibre. By action of the bend inducer (304) a change in value of the environmental parameter imparts a bending force on the optical fibre.

Abstract: Performance improvement of an all-optical analog-to-digital converter (AOADC) addresses both RF and optical modeling of a leaky waveguide based optical spatial light modulator (SLM) using electro-optic (E-O) material. The E-O polymer provides improved sensitivity for SLM and achieves a broader bandwidth due to better velocity matching between RF and optical waves.

Abstract: Provided is an optical densitometer for measuring a density of a gas or liquid of interest, the optical densitometer comprising: a light source capable of introducing light into a core layer; a detector capable of receiving the light that has propagated through the core layer; and an optical waveguide, the optical waveguide comprising: a substrate; and the core layer comprising a light propagation portion capable of propagating the light in an extending direction of the light propagation portion, and a diffraction grating portion, the diffraction grating portion comprising a diffraction grating region and an extension region connected to the diffraction grating region, and a first optical coupling region included in the extension region and a second optical coupling region included in the light propagation portion being optically coupled with respect to the light propagating through the core layer.

Abstract: Structures including a waveguide core and methods of fabricating a structure including a waveguide core. The structure comprises a photonics chip including a first chip region, a second chip region, a first waveguide core in the first chip region, and a second waveguide core in the second chip region. The first chip region adjoins the second chip region along a boundary. The first waveguide core includes a first tapered section, and the second waveguide core includes a second tapered section positioned across the boundary from the first tapered section. The first tapered section has a first width dimension that increases with increasing distance from the boundary, and the second tapered section has a second width dimension that increases with increasing distance from the boundary.

Abstract: A photonic integrated circuit (PIC) in which some optical waveguides have laterally tilted waveguide cores used to implement passive polarization-handling circuit elements, e.g., suitable for processing polarization-division-multiplexed optical communication signals. Different sections of such waveguide cores may have continuously varying or fixed lateral tilt angles. Different polarization-handling circuit elements can be realized, e.g., using different combinations of end-connected untilted and laterally tilted waveguide-core sections. In some embodiments, laterally tilted waveguide cores may incorporate multiple-quantum-well structures and be used to implement active circuit elements. At least some embodiments beneficially lend themselves to highly reproducible fabrication processes, which can advantageously be used to achieve a relatively high yield of the corresponding PICs during manufacture.

Abstract: An optomechanical inertial reference mirror combines an optomechanical resonator with a reflector that serves as an inertial reference for an atom interferometer. The optomechanical resonator is optically monitored to obtain a first inertial measurement of the reflector that features high bandwidth and high dynamic range. The atom interferometer generates a second inertial measurement of the reflector that features high accuracy and stability. The second inertial measurement corrects for drift of the first inertial measurement, thereby resulting in a single inertial measurement of the reflector having high bandwidth, high dynamic range, excellent long-term stability, and high accuracy. The reflector may be bonded to the resonator, or formed directly onto a test mass of the resonator. With a volume of less than one cubic centimeter, the optomechanical inertial reference mirror is particularly advantageous for portable atomic-based sensors and systems.

Abstract: Roughly described, an optical device includes a first waveguide having a first core sheathed by a first cladding, and a second waveguide having a second core. A terminal portion of second core is disposed under a terminal portion of the first core and sheathed by the first core. The refractive index of the second core is higher than that of the first core, and the index of the first core, at least in the terminal portion of the first waveguide, is higher than that of the first cladding. The second core is structured under the terminal portion of the first core so that light traveling in the second core and directed toward the end of the second core is guided along the second core and coupled into the first core, and vice-versa.

Abstract: Structures for an optical coupler and methods of fabricating a structure for an optical coupler. The structure includes a first waveguide core having a first tapered section and a second waveguide core having a second tapered section positioned adjacent to the first tapered section of the first waveguide core. The second tapered section is positioned with a lateral offset in a lateral direction relative to the first tapered section. The second tapered section is positioned with a vertical offset in a vertical direction relative to the first tapered section.

Abstract: A guided-wave-driven metasurface antenna includes an input for receiving a guided wave; an output for outputting a free-space wave; and a spatial frequency mixer connected between the input and the output for converting the guided wave to the free-space wave. The spatial frequency mixer is implemented by a metasurface of the antenna. The superheterodyne metasurface can be fabricated with high accuracy using lithography step similar to conventional waveguides made by the well-established semiconductor processing technology, making their integration with PICs straightforward.

Abstract: To reduce the size while being able to accurately monitor light of a plurality of wavelengths. An optical multiplexing circuit includes: a plurality of branching units each configured to divide light output from a corresponding one of a plurality of input waveguides; a multiplexing unit configured to multiplex beams each being one beam of the light divided by each of the plurality of branching units; an output waveguide configured to output the light multiplexed by the multiplexing unit; and a plurality of monitoring waveguides each configured to output another beam of the light divided by each of the plurality of branching units, wherein at least one monitoring waveguide of the plurality of monitoring waveguides includes a bent waveguide constituted by a rib-shaped waveguide.

Abstract: A whispering gallery mode inertial sensor includes a whispering gallery mode resonator; an evanescent coupler configured to couple with an evanescent field of the resonator so that light is transmitted to and received from the resonator by the coupler; a displacement sensor configured to determine a displacement of the resonator according to the light received from the resonator by the coupler; a controller configured to determine an acceleration and/or rate of rotations experienced by the resonator based on the displacement of the resonator, the controller being further configured to apply a restoring force to the resonator in a closed feedback loop based on the displacement of the resonator in order to maintain a predetermined mechanical state of the resonator; and a timing sensor configured to determine a timing signal based on an optical frequency comb produced by the resonator.

Abstract: An optical waveguide device includes a pair of waveguides. One of the waveguides includes a first core formed in a conversion region and a third core formed in an exit region. The other of waveguides includes a second core formed in the conversion region and a fourth core formed in the exit region. Cross-sectional areas of the first and second cores are different from each other at an input end. Distributions of a refractive index of the first and second cores are respectively asymmetric in a perpendicular direction. A quantitative relation provided at the input end between an effective refractive index of an odd mode of TE0 and an effective refractive index of an even mode of TM0 is opposite to the quantitative relation provided at the output end. Cross-sectional areas of the third and fourth cores are different from each other at an output end.

Abstract: A light interference system is provided. The light interference system includes a light source configured to generate a measurement light; a fiber configured to propagate therethrough the measurement light; and a measurement device. The fiber includes a single-mode fiber, a multimode fiber and a connector connecting the single-mode fiber and the multimode fiber. A tip end of the fiber is formed of the multimode fiber, and an end surface of the tip end of the fiber is configured to emit the measurement light to a measurement target object and receive a reflection light from the measurement target object. The measurement device is configured to measure physical property of the measurement target object based on the reflection light.

Abstract: The present disclosure relates to a method of forming a tapered optical fiber, where the optical fiber has a cladding encasing a core and has an initial outer diameter. The method involves applying opposing forces to spaced apart sections of the optical fiber. The spaced apart sections define a length portion representing a waist region. While applying the opposing forces, simultaneously applying heat to the waist region to gradually produce a taper of the optical fiber within the waist region. The taper has a first diameter at a midpoint of the waist region which is less than the initial outer diameter. An etch operation is then performed by chemically etching at least a subportion of the waist region of the optical fiber to reduce the subportion to a second diameter which is less than the first diameter.

Abstract: Embodiments of the disclosure provide an optical polarizer with a varying vertical thickness, and methods to form the same. An optical polarizer according to the disclosure may include a first waveguide core over a semiconductor substrate. A first cladding material is on at least an upper surface of the first waveguide core. A second waveguide core over the first waveguide core and above the first cladding material. The second waveguide core includes a first segment having a vertical thickness that varies along a length of the first segment. A second cladding material is at least partially surrounding the second waveguide core. Transfer of one of a transverse electric (TE) mode signal and a transverse magnetic (TM) mode signal from the first waveguide core to the second waveguide core occurs between the first segment of the second waveguide core and the first waveguide core.

Abstract: There is provided an optical waveguide that performs propagation only in a reference mode at a first wavelength. Communication is performed using light of a second wavelength that enables the optical waveguide to perform propagation in at least a first order mode in addition to the reference mode. When light entering the optical waveguide deviates with respect to an optical axis or deviates angularly, propagation is performed in at least the first order mode in addition to the reference mode, the first order mode being generated due to the deviation with respect to the optical axis or the angular deviation. This results in a reduction in a loss of coupling of optical power. This makes it possible to relax the accuracy with respect to a deviation with respect to an optical axis or an angular deviation, and thus to reduce costs.

Abstract: A method for making a multimode interference (MMI) coupler with an arbitrary desired splitting ratio includes forming a thin-film of silicon-nitride material overlying a SOI substrate. The method further includes obtaining geometric parameters of a standard MIMI coupler including a rectangular MMI block and one input port and two output ports in taper shape with one of standard splitting ratios under self-imaging principle which is close to the desired splitting ratio. Additionally, the method includes tunning the input port to an off-center position at front edge of the MMI block. The method further includes making a first output port to a first off-center position flushing with a side edge of the MMI block, adjusting a second output port to a second off-center position. The method includes tunning the MMI block to obtain optimized geometric parameters for approaching the selected arbitrary splitting ratio, and etching the thin-film of silicon-nitride material.

Abstract: Structures for a wavelength-division multiplexing filter and methods of forming a structure for a wavelength-division multiplexing filter. The structure includes a first slab having a first perimeter, a first waveguide core coupled to the first slab, and a plurality of second waveguide cores coupled to the first slab. A second slab is positioned to overlap with the first slab. The second slab includes a second perimeter and openings that are distributed inside the second perimeter. The openings of the second slab penetrate through the second slab.

Abstract: An optical coherent transceiver comprising a polarization and phase-diversity coherent receiver and a polarization and phase-diversity modulator on the same substrate interfaced by three grating couplers, one grating coupler coupling in a signal, one grating coupler coupling in a laser signal, and a third grating coupler coupling out a modulated signal.

Abstract: The present invention has an object to provide an optical fiber test method and an optical fiber test apparatus for measuring a mode dependent loss and an inter-modal crosstalk in a fundamental mode and a first higher-order mode at a connection point of a few-mode fiber. In the optical fiber test method and test apparatus according to the present invention, the mode dependent loss and the inter-modal crosstalk in the fundamental mode and the first higher-order mode at the connection point are calculated by using an approximation expression of an inter-modal coupling efficiency that is obtained in approximating electric field distributions of the fundamental mode and the first higher-order mode in a few-mode fiber by Gaussian function and Hermite Gaussian function.

Abstract: An optical device includes a first multi-mode waveguide, a first optical coupler coupled to the first multi-mode waveguide, the first coupler being tapered and curved, and a first single-mode waveguide having a first end coupled to the first optical coupler. The optical device maybe used in an optical delay device. A method of propagating light in a first multi-mode waveguide toward a first optical coupler, propagating the light in the first optical coupler toward a first single-mode waveguide, the first optical coupler being tapered and curved, and propagating the light along the first single-mode waveguide is also disclosed.

Abstract: An integrated wavelength division multiplexer is described. The integrated wavelength division multiplexer may include a first waveguide core defining a first propagation axis and configured to guide light of a first wavelength and light of a second wavelength, and a second waveguide core defining a second propagation axis and configured to guide the light of the second wavelength. A first portion of the second propagation axis for which the first waveguide core and second waveguide core may be overlapping is oriented at a non-zero angle relative to the first propagation axis. The first waveguide core and second waveguide core may be configured relative to each other to adiabatically couple the light of the second wavelength between the first and second waveguide cores.

Abstract: An apparatus for laser processing a material including an optical fibre, at least one squeezing mechanism, and a lens. The optical fibre is a multimode optical fibre in which laser radiation propagates in a first optical mode and in a second optical mode. The squeezing mechanism includes at least one periodic surface defined by a pitch. The periodic surface is located adjacent to the optical fibre. The pitch couples the first and second optical modes together. The first optical mode is defined by a first mode order. The second optical mode is defined by a second mode order which is higher than the first mode order. The squeezing mechanism squeezes the periodic surface and optical fibre together with a squeezing force thereby coupling the first optical mode to the second optical mode.

Abstract: The present invention relates to a polymer optical waveguide including: a core; an under-cladding; and an over-cladding, in which the polymer optical waveguide includes a coupling section and an optical waveguide section that are provided along a light propagation direction, the polymer optical waveguide includes portions having different core widths along the light propagation direction, and when a core width at a portion a having a narrowest core width is denoted Wa (?m) and a core height at the portion a is denoted Ha (?m), Ha is 1.3 ?m or more and 4.5 ?m or less, and Ha/Wa is 1.15 or less.

Abstract: An optical mode converter for coupling between photonic integrated circuit (PIC) and optical fiber of different mode sizes is illustrated. The optical mode converter includes a waveguide assembly including a Single waveguide structure, a Multi-layer waveguide structure, and a Transitional waveguide structure. The Single waveguide structure includes a single waveguide. The dimension and propagation constant of a first end, of the single waveguide, is similar to a waveguide of a photonic integrated circuit (PIC). Furthermore, the Multi-layer waveguide structure included a multi-layer waveguide. Further, the Transitional waveguide structure is formed at a transitional structure. The Transitional waveguide structure allows transition of an optical mode between the Single waveguide structure and Multi-layer waveguide structure.

Abstract: An optical modulator includes an input waveguide having a first width enabling a propagation of a light-beam in a single-mode, a tapered waveguide having an input end connected to the input waveguide and an output end having a second width larger than the first width, an optical demultiplexer having an input port connected to the output end, a first output port connected to a first arm waveguide, and a second output port connected to a second arm waveguide connected to the second output port, a first electrode disposed on the first arm waveguide, and a second electrode disposed on the second arm waveguide. The first arm waveguide has a third width larger than the first width. The first arm waveguide is located within a first strip region. The first strip region having a fourth width twice as large as the third width.

Abstract: Structures for a directional coupler and methods of fabricating a structure for a directional coupler. A first waveguide core has a first section, a second waveguide core has a second section laterally adjacent to the first section, a third waveguide core has a first taper, a second taper, and a third section longitudinally positioned between the first taper and the second taper, and a fourth waveguide core has a first taper, a second taper, and a fourth section longitudinally positioned between the first taper and the second taper. The fourth section is laterally adjacent to the third section, and the third section and the fourth section are positioned either over or under the first section and the second section.

Abstract: One optical antenna coupler includes a base body having a first waveguide and a second waveguide and a plurality of antenna coupler elements positioned above an upper surface of the base body that are adapted to be irradiated by an incident light. The plurality of antenna coupler elements includes at least one variable optical characteristics (VOC) antenna coupler element that comprises a VOC material, wherein the at least one VOC antenna coupler element is operatively coupled to a first energy source. The VOC antenna coupler element is adapted to be transitioned from a metallic state to an insulator state and vice versa. In the metallic state, substantially all of the incident light is directed out of the optical antenna coupler via the first waveguide and, in the insulator state, substantially all of the incident light is directed out of the optical antenna coupler via the second waveguide.

Abstract: An optical phase shifter may include a waveguide core that has a top surface, and a semiconductor contact that is laterally displaced relative to the waveguide core and is electrically connected to the waveguide core. A top surface of the semiconductor contact is above the top surface of the waveguide core. The waveguide core may include a p-type core region and an n-type core region. A p-type semiconductor region may be in physical contact with the n-type core region of the waveguide core, and an n-type semiconductor region may be in physical contact with the p-type core region of the waveguide core. A phase shifter region and a light-emitting region may be disposed at different depth levels, and the light-emitting region may emit light from a phase shifter region that is in a position adjacent to the light-emitting region.

Abstract: Systems and methods for coupling optical fiber to a photonic chip are described. The apparatus may include a low index contrast waveguide overlapping a region of a photonic chip, a high index contrast waveguide at least partially embedded within the overlapped region of the photonic chip, where the high index contrast waveguide comprises a tapered region and a fixed-width routing region, and where the tapered region comprises an adiabatic crossing region and a wide waveguide region connecting the adiabatic crossing region and the fixed-width routing region. A rate of increase of the width of the high index contrast waveguide with respect to position along the length of the high index contrast waveguide is substantially non-linear within the adiabatic crossing region and substantially asymmetric about a minimum slope point.

Abstract: An optical phase shifter may include a waveguide core that has a top surface, and a semiconductor contact that is laterally displaced relative to the waveguide core and is electrically connected to the waveguide core. A top surface of the semiconductor contact is above the top surface of the waveguide core. The waveguide core may include a p-type core region and an n-type core region. A p-type semiconductor region may be in physical contact with the n-type core region of the waveguide core, and an n-type semiconductor region may be in physical contact with the p-type core region of the waveguide core. A phase shifter region and a light-emitting region may be disposed at different depth levels, and the light-emitting region may emit light from a phase shifter region that is in a position adjacent to the light-emitting region.

Abstract: An optical device comprises first, second and third elements fabricated on a common substrate. The first element comprises an active waveguide structure supporting a first optical mode, the second element comprises a passive waveguide structure supporting a second optical mode, and the third element, at least partly butt coupled to the first element, comprises an intermediate waveguide structure supporting intermediate optical modes. If the first optical mode differs from the second optical mode by more than a predetermined amount, a tapered waveguide structure in at least one of the second and third elements facilitates efficient adiabatic transformation between the second optical mode and one of the intermediate optical modes. No adiabatic transformation occurs between any of the intermediate optical modes and the first optical mode. Mutual alignments of the first, second and third elements are defined using lithographic alignment marks.

Abstract: An optical coupler (40; 50) comprises a substrate (41). A first waveguide element (45) is provided in a first layer with respect to the substrate, wherein the first waveguide element (45) comprises a first end (45a) and a second end (45b), and wherein the first end (45a) of the first waveguide element (45) is coupled to input/output light to/from a first end of the optical coupler. A second waveguide element (43) is provided in a second layer, the second layer arranged adjacent to the first layer, wherein the second waveguide element (43) comprises a first end (43a) and a second end (43b), and wherein the first end (43a) of the second waveguide element (43) is coupled to input/output light to/from a second end of the optical coupler.

Abstract: In one example, an optical device may include a waveguide having a core index of refraction that decreases along a length of the waveguide and an edge index of refraction of the waveguide that is constant along the length of the waveguide. The central rays of the optical signals travelling through the waveguide may be refracted towards higher radii while the outer rays propagate unaffected. The optical device may decrease dispersion of the optical signals travelling through an optical fiber.

Abstract: According to one example, the present application discloses an optical circuit comprising a grating to receive input light of mixed polarizations and output light of a same polarization to a first waveguide and a second waveguide. The first waveguide and second waveguide are optically coupled to a plurality of resonators that are coupled to a plurality of gratings that are to output light of mixed polarizations.

Abstract: The optical fiber according to the present disclosure is an optical fiber having a pure silica core which is a step index core through which an LPm1 mode with an effective area of 250 ?m2 or more is propagated by setting a relative refractive index difference to 0.60% or less, considering an effective cutoff condition, and only 2 or more modes or the LPm1 mode are propagated, with the optical fiber as the transmission line.

Abstract: Majorana photons are transmitted through a biological tissue sample to image the tissue. The Majorana photons have a circular polarization, a radial polarization or an azimuthal polarization. The transmitted photons are processed to produce a digital image of the biological tissue sample.

Abstract: Structures for a waveguide bend and methods of fabricating a structure for a waveguide bend. A first waveguide core has a first section, a second section, and a first waveguide bend connecting the first section with the second section. The first waveguide core has a first side surface extending about an outer radius of the first waveguide bend. A second waveguide core also has a first section, a second section, and a second waveguide bend connecting the first section with the second section. The second waveguide core has a second side surface extending about an outer radius of the second waveguide bend. The first waveguide bend is spaced from the second waveguide bend in a first non-contacting relationship with a gap between the first side surface and the second side surface. The gap has a perpendicular distance selected to permit optical signal transfer between the first and second waveguide bends.

Abstract: An optical transmission system according to the present disclosure is a mode multiplexed optical transmission system using a multi-mode optical fiber in which a plurality of propagation modes propagate as a transmission line, the optical transmission system including an optical fiber transmission line (83) that includes an optical fiber with two or more propagation modes; and a plurality of mode converters (91) that are configured to generate mode coupling between at least one pair of the propagation modes, in which a variation in an installation interval of the plurality of mode converters (91) is equal to or less than a threshold value determined by the transmission line length (Lt) of the optical fiber transmission line (83).

Abstract: Structures including a waveguide core and methods of fabricating a structure including a waveguide core. A back-end-of-line interconnect structure has an interlayer dielectric layer and a cap layer stacked over the interlayer dielectric layer. A waveguide core includes a section arranged beneath the cap layer. The waveguide core has a first index of refraction that varies as a function of width, and the cap layer has a second index of refraction. The section of the waveguide core has a width that is selected such that the first index of refraction is substantially equal to the second index of refraction to provide phase matching effective for coupling a portion of an optical signal from the waveguide core to the cap layer.

Abstract: The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting photon detectors. In one aspect, a photon detector includes: (1) a first waveguide configured to guide photons from a photon source; (2) a second waveguide that is distinct and separate from the first waveguide and optically-coupled to the first waveguide; and (3) a superconducting component positioned adjacent to the second waveguide and configured to detect photons within the second waveguide.

Abstract: An optical fiber, used in a laser device, propagates light having a wavelength of 1060 nm through a core in at least an LP01 mode and an LP11 mode. A difference between a propagation constant of light in the LP01 mode and a propagation constant of light in the LP11 mode is 1850 rad/m or more and 4000 rad/m or less.

Abstract: An optical device package includes: (1) a waveguide, the waveguide including: a main body; and multiple forks, wherein each of the plurality of forks has a tapering end and is extended from the main body, and wherein each of the tapering ends of the forks includes a facet for receiving light; and (2) an optical fiber having a surface configured to output the light into the waveguide; wherein a lateral distance between the surface of the optical fiber and at least one of the facets is less than about 25 micrometers (?m).

Abstract: An optical transmission system includes an optical transmission apparatus and an optical reception apparatus. The optical transmission apparatus includes a conversion unit that converts multiple binary data sequences into data in a predetermined signal format; a coding unit that generates multiple pieces of coded data by performing predetermined coding on each of the multiple pieces of converted data; an optical signal generation unit that generates multiple optical signals by converting the multiple pieces of coded data into optical signals; and a mode multiplexer that converts the multiple optical signals into different modes, generates a mode-division multiplexed optical signal by mode-division multiplexing the optical signals, and transmits the generated mode-division multiplexed optical signal to the optical reception apparatus.

Abstract: In the examples provided herein, a polarization diversity receiver system includes a loop waveguide, and a two-dimensional grating coupler formed on the loop waveguide to couple light impinging on the grating coupler having a first polarization into the loop waveguide in a first direction, and to couple light having a second polarization orthogonal to the first polarization into the loop waveguide in a second direction. The system also includes a first output waveguide positioned near the loop waveguide in a first coupling region, a first distributed perturbation having a first resonant wavelength in the first coupling region to cause coupling of light at the first resonant wavelength between the loop waveguide and the first output waveguide, and a first photodetector to detect light propagating out of a first end and a second end of the first output waveguide.

Abstract: The invention relates to an optical fiber mounted photonic integrated circuit device, wherein the tolerance for positioning in terms of the coupling between the single mode optical fibers and the optical waveguides provided on the photonic integrated circuit device is increased. An optical waveguide core group is provided in such a manner where a plurality of optical waveguide cores having a portion that is tapered in the direction of the width within a plane are aligned parallel to each other at intervals that allow for mutual directional coupling and that are narrower than the width of the core of the single mode optical fiber, and the inclined connection end surface of the single mode optical fiber and the upper surface of an end portion of the optical waveguide cores face each other for coupling.

Abstract: The invention relates to a system and a method for transmission over optical fiber (130) with mode or core scrambling. The system comprises a spatio-temporal encoder (110) and a plurality of modulators (1251, . . . , 125n) associated, respectively, with separate propagation modes or cores of said fiber, each modulator modulating a laser beam. Said fiber comprises a plurality of slices (1301, . . . , 130L), an amplifier (140l) being provided between any two consecutive slices of the optical fiber. A mode scrambler (150l) is associated with each amplifier in order to perform a permutation of said modes between at least two consecutive slices.

Abstract: The invention concerns a method for characterizing mode group properties of multimodal light traveling through an optical component, comprising: providing a Mode Group Separating optical fiber in an optical path between a light source and said optical component; launching reference pulses of light with a wavelength ?t from said light source through said Mode Group Separating optical fiber into said optical component at discrete intervals between a core center and a core radius of said fiber. The Mode Group Separating optical fiber is a multimode fiber with an ?-profile graded index core with an ?-value chosen such that said fiber satisfies the following criterion at the wavelength ?t: ? ?? ? · L ? ? ? T REF > 4 where: ?? is a time delay difference between consecutive mode groups; L is a length of said fiber; ?TREF is a Full Width at Quarter Maximum of said reference pulses.