Abstract: Embodiments relate to a branching waveguide circuit where two or more waveguides branch from a main waveguide defining between them an intermediate region ranging from said main waveguide. The intermediate region comprises a plurality of holes of cladding material extending from the top of the core layer into intermediate material, said holes being arranged so that the depth of said holes increases away from said main waveguide with an average slope of the hole depth versus distance to main waveguide. This way, loss due to transition between the main and branching waveguides may be reduced.

Abstract: An integrated optical coupler including in the medium separating a first integrated waveguide from a second substantially parallel integrated waveguide, a succession of strips parallel to one another and orthogonal to the general direction of the waveguides, said strips being made of a material having an absorption preventing the propagation of an electromagnetic wave across its volume, and having: a length H equal to k?/2nmedium, where k is an integer, ? is the central wavelength used, and nmedium is the optical index of the medium between the waveguides; a period P smaller than ?/2nmedium; and ends at a distance shorter than ?/10 from the waveguides.

Abstract: A laser array optical coupling assembly may be used to couple a laser array to an arrayed waveguide grating (AWG), for example, in an optical transmitter in a wavelength division multiplexed (WDM) optical communication system. The laser array optical coupling assembly may include an optical fiber tip array with polished optical fiber tips providing a reduced mode field diameter to improve coupling efficiency with the laser array. The laser array optical coupling assembly may also include a direct coupling of the laser array to the AWG with modified AWG inputs reducing the mode field diameter to improve coupling efficiency with the laser array. The laser array optical coupling assembly may be used, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON) or in other transmitters or transceivers in a WDM system capable of transmitting and receiving optical signals on multiple channel wavelengths.

Abstract: A polarization-insensitive optical receiver for demodulating a phase-modulated input optical signal is provided. The optical receiver includes successively a polarization splitter, a first and second interferometric modules including respective delay lines, and a plurality of detectors. The input optical signal is split into two substantially orthogonally-polarized components, which are launched along respective optical paths into the corresponding interferometric modules where they demodulated and subsequently recombined prior to being detected by the plurality of detectors. Advantageously, the optical receiver allows mitigating undesired discrepancies between the optical paths traveled by the two polarization components by arranging the respective delay lines of the interferometric modules into intertwined spiraling structures.

Abstract: A photonic integrated circuit (PIC) having a waveguide-grating coupler with two evanescently coupled waveguides. The first waveguide is fabricated using materials suitable for manufacturing active optical elements in the PIC. The second waveguide is fabricated using materials capable of providing a relatively high index-of-refraction contrast for the constituent waveguide grating. The waveguide-grating coupler is compatible with the III-V semiconductor technology while being relatively easy to fabricate on an industrial scale.

Abstract: Arrayed waveguide grating (AWG) circuits are disclosed, having different radii in the slab regions to supplement and/or replace other mechanical techniques which enable athermal AWGs. Dual band, interleaved pairs of athermal AWGs are also disclosed, with improved cost, space and center wavelength properties, for, e.g., optical line terminal (OLT), and remote node (RN) applications.

Abstract: An optical device includes: an optical waveguide; and a plurality of diffraction grating layers, provided along the optical waveguide, each including a diffraction grating defined by a discontinuous first semiconductor layer and a second semiconductor layer having a refractive index different from a refractive index of the first semiconductor layer and burying the first semiconductor layer, one diffraction grating layer of the plurality of diffraction grating layers including a third semiconductor layer being continuous with the diffraction grating and made from a material different from materials of the first and the second semiconductor layers.

Abstract: An optical waveguide and a bi-directional transceiver are provided. A single mode optical fiber has one end coupled to one end of a hollow optical fiber and an opposite end having a slope plane, thereby separating optical signals travelling in opposite directions from each other. Manual alignment for an optical system is easily realized without the need for additional optical elements, so that the light transmission/reception performance of the optical waveguide is improved and the structure of the optical waveguide is smaller.

Abstract: A data transport card comprising an interface to receive high speed data streams from at least one client, and a pluggable conversion module which converts said data streams into optical data signals and couples these optical data signals into at least one wavelength division multiplexing channel for transport of said optical data signals via an optical fiber.

Abstract: Consistent with one example of the disclosed implementations, a photonic integrated circuit (PIC) may be provided that includes s group of lasers and an arrayed waveguide grating (AWG) disposed on a substrate. Each laser in the group may supply an optical signal, such that each optical signal has a different wavelength. Each laser may be tunable to at least two designated wavelengths, which are separated from one another by a free spectral range (FSR) of the AWG. As a result, the optical signals provided from each laser may be combined by the AWG, regardless of which designated wavelength the optical signals have. Accordingly, a PIC may be provided that has a relatively simple construction but can supply optical signals having tunable wavelengths.

Abstract: A single-stage 1×5 grating-assisted wavelength division multiplexer is provided. A grating-assisted asymmetric Mach-Zehnder interferometer, a plurality of grating-assisted cross-state directional couplers and a plurality of novel side-band eliminators are combined to form the multiplexer. Only general gratings are required, not Bragg grating, for 5-channel wavelength division multiplexing in a single stage. A nearly ideal square-like band-pass filtering passband is obtained. The present disclosure can be used as a core device in IC-to-IC optical interconnects for multiplexing and demultiplexing of an optical transceiver. The present disclosure has a small size and good performance.

Abstract: Fiber structure including a core and a cladding, a central microstructure having a first plurality of longitudinal holes and which is adapted for guiding optical radiation and for birefringence in the core. Also included is a side microstructure having a second plurality of longitudinal holes is provided, wherein the side microstructure partly surrounds the central microstructure and provides a predetermined mechanical anisotropy, a pressure responsive unit for converting an isotropic pressure force to birefringence changes on the core, a lateral force responsive unit for converting a directional pressure force to birefringence changes on the core, a temperature responsive unit for converting temperature to birefringence changes on the core, and a birefringence responsive unit for converting birefringence in the core to wavelength information.

Abstract: A polymer waveguide for coupling with one or more light transmissible devices, a method of fabricating a polymer waveguide for coupling with one or more light transmissible devices, and a method of coupling a polymer waveguide with one or more light transmissible devices. The polymeric waveguide comprises a grating structure.

Abstract: Provided is an optical sensor and an optical sensor fabricating method. The optical sensor includes: a substrate; and an ommatidia located on or inside the substrate, the ommatidia comprising a microlens which receives light, an optical waveguide which transfers the light received through the microlens, and a cone structure comprising a first end connected to the microlens and a second end connected to the optical waveguide, the cone structure having a diameter or a width decreasing in a direction from the first end to the second end.

Abstract: A method and apparatus use a photonic-crystal fiber having a very large core while maintaining a single transverse mode. In some fiber lasers and amplifiers having large cores problems exist related to energy being generated at multiple-modes (i.e., polygamy), and of mode hopping (i.e., promiscuity) due to limited control of energy levels and fluctuations. The problems of multiple-modes and mode hopping result from the use of large-diameter waveguides, and are addressed by the invention. This is especially true in lasers using large amounts of energy (i.e., lasers in the one-megawatt or more range). By using multiple small waveguides in parallel, large amounts of energy can be passed through a laser, but with better control such that the aforementioned problems can be reduced. An additional advantage is that the polarization of the light can be maintained better than by using a single fiber core.

Abstract: Provided is a high-speed and highly efficient semiconductor light-receiving element with small dependence on an incident light polarization direction. A semiconductor light-receiving element according to one aspect of the present invention includes a semiconductor layer including a light-absorbing layer 4, an MSM electrode 1 that is provided over the semiconductor layer, forms a Schottky junction with the semiconductor layer, and includes a slit-like opening, an anti-reflective film 2 formed over the semiconductor layer and the MSM electrode 1, and a Bragg reflection multilayer film 6 provided to a lower part of the semiconductor layer. The MSM electrode 1 includes a period capable of exciting surface plasmon to incident light of TM polarization, and obtains sufficient transmittance to the incident light of TE polarization.

Abstract: Optical devices using double-groove diffraction gratings having periodic sets of TiO2 elements on one or more surfaces of an SiO2 substrate are disclosed. First order components of incident polarized light coupled into the substrate are reflected so as to propagate through the substrate to terminus points where they either change direction for further propagation or exit the substrate. A windshield display system using the principles of the invention is disclosed.

Abstract: An arrayed waveguide grating optical multiplexer/demultiplexer according to the present invention including an input channel waveguide, an input slab waveguide, an arrayed waveguide, a polarization dependence eliminating means, an output slab waveguide, a temperature compensating means, and an output channel waveguide is characterized in that the temperature compensating means compensates for the temperature dependence of the optical path lengths in the channel waveguides of the arrayed waveguide, and the polarization dependence eliminating means eliminates the temperature dependence and the polarization dependence of the arrayed waveguide grating optical multiplexer/demultiplexer at the same time.

Abstract: A structure that is located adjacent to a measurement target on a substrate is used to convert incident radiation from an optical metrology device to be in-plane with the measurement target. The structure may be, e.g., a grating or photonic crystal, and may include a waveguide between the structure and the measurement target. The in-plane light interacts with the measurement target and is reflected back to the structure, which converts the in-plane light to out-of-plane light that is received by the optical metrology device. The optical metrology device then uses the information from the received light to determine one or more desired parameters of the measurement target. Additional structures may be used to receive light that is transmitted through or scattered by the measurement target if desired.

Abstract: An optical device includes a light-transmitting medium positioned on a base. The light-transmitting medium at least partially defines a free propagation region through which light signals travel. A reflective grating includes stepped reflecting surfaces positioned such that light signals that travel through the free propagation region are received by the reflecting surfaces. The reflecting surfaces are configured to reflect the light signal back into the free propagation region such that the light signals associated with different wavelengths separate as the light signals travel through the free propagation region. At least a portion of the reflecting surfaces each includes an overlapping region. Additionally, at least a portion of the reflecting surfaces each includes an overlapped region and un un-overlapped region. The reflecting grating is configured such that the light signals travel toward the overlapped regions and the un-overlapped regions before being reflected.

Abstract: A multiplexer-demultiplexer including: an AWG chip including a first input-output waveguide, a first slab waveguide connected thereto, an arrayed waveguide connected thereto and formed of parallel channel waveguides of different lengths, a second slab waveguide connected thereto, and second input-output waveguides connected thereto; a base plate joined to an underside of the chip; a fixed piece and a movable piece formed by the chip and the base plate being cut across the first or second slab waveguide; a reference plate to which the fixed piece is joined and against which the movable piece is abutted; a member bridging between these pieces and compensating a temperature-dependent shift of a light transmission center wavelength of the multiplexer-demultiplexer by expanding/contracting according to a temperature change and changing relative positions of the pieces; and a clip sandwiching the reference plate and the movable piece allowing the piece to slide on the plate.

Abstract: A multiplexer/demultiplexer includes: a waveguide chip including a first chip and a second chip that are divided by a plane and obtained by cutting, together with a substrate, in a direction crossing an optical axis, a first slab waveguide of an AWG including the first slab waveguide and a second slab waveguide that are formed on the substrate; a first base to which the first chip is fixed; a second base separated from the first base and to which the second chip is fixed; and a member that has one end fixed to the first base or chip and another end fixed to the second base or chip, in a state in which cut surfaces of the first and second chips face each other, and that is configured to move the first base and the second base relatively to each other along the plane by expanding/contracting when temperature changes.

Abstract: An optical de-MUX includes a sub-wavelength grating that magnifies an input optical signal. In particular, along a direction perpendicular to a propagation direction of the optical signal, the sub-wavelength grating has a spatially varying effective index of refraction that is larger at a center of the sub-wavelength grating than at an edge of the sub-wavelength grating. Moreover, the optical de-MUX includes an optical device that images and diffracts the optical signal using a reflective geometry, and which provides different diffraction orders to output ports. For example, the optical device may include an echelle grating.

Abstract: Disclosed is a grating coupler which includes an optical waveguide transferring an optical signal; and a diffraction grating formed on the optical waveguide. The diffraction grating includes protrusions continuously formed and the protrusions have different heights.

Abstract: The present disclosure provides optical waveguide coupling devices and associated methods. In one example, an optical waveguide coupling device can comprise a dielectric grating coupler, a first optical waveguide attached to a first surface of the dielectric grating coupler, and a second optical waveguide attached to a second surface of the dielectric grating coupler. The second optical waveguide can be oriented opposed to the first optical waveguide allowing for communication therebetween via the sub-wavelength grating. Additionally, the dielectric grating coupler can comprise a first dielectric material; a sub-wavelength grating attached to the first dielectric material, the sub-wavelength grating having a higher refractive index than the first dielectric material; and a second dielectric material optically coupled to the sub-wavelength grating.

Abstract: A wavelength tunable filter and a wavelength tunable laser module are a codirectional coupler type whose characteristics do not vary significantly with a process error. They are structured so as to include a semiconductor substrate which has a first optical waveguide and a second optical waveguide. The first and the second optical waveguides are extended from a first side of the semiconductor substrate to an opposing second side thereof. The first optical waveguide includes a first core layer, which has a planar layout having periodic convexes and concaves, and a pair of electrodes, which vertically sandwich the first core layer. The second optical waveguide includes a second core layer, which has a lower refractive index than the first core layer. Further, a layer having the same composition and film thickness as the second core layer is placed under the first core layer.

Abstract: A method of measuring fiber twist in a multi-core optical fiber bearing an FBG with polarization dependent reflectivity. The state of polarization of the launched light is adjusted until the reflected FBG wavelength is maximal, indicating that light reaching the FBG is linearly polarized, and the polarization axis of the light reaching the FBG is aligned with the slow birefringent axis of the FBG; the SOP of launched light is now measured. Bending experienced by the fiber is measured conventionally, and birefringence produced by bending of the multi-core optical fiber is calculated. A candidate amount of twist between the launch location and the FBG is proposed, and the corresponding twist-induced birefringence is calculated. When calculations show that light with the launched SOP becomes linearly polarized and aligned with the FBG after traversing a fiber section with the calculated birefringences and proposed rotation, the amount of twist has been properly identified.

Abstract: An integrated optical circuit including an operational submicronic waveguide associated with an operational grating intended for the coupling with an optical fiber, further including an alignment grating, identical to the operational grating, associated with a blind waveguide and arranged at a known distance from the operational grating.

Abstract: A triplexer including an optics block including a first port configured to receive a first light beam at a first wavelength and a second light beam at a second wavelength, and a second port configured to receive a third light beam at a third wavelength, a bounce cavity between the first and second ports, the bounce cavity being formed by opposing reflective elements adjacent respective surfaces of the optics block, a first grating opposite the first port, the first grating receiving all three light beams at substantially a same location thereon, the first grating configured to provide the first and second light beams to the bounce cavity and the third light beam to the first port, and a second grating opposite the second port, the second grating receiving the first and second light beams at spatially separated portions thereon.

Abstract: The present invention is an optical interconnect structure characterized by that it comprises an optical waveguide comprising a first core and a connective optical waveguide which is formed on the optical waveguide and comprises a second core, and that a first diffraction grating formed in the first core and a second diffraction grating formed into the second core are arranged such that at least a part of the former faces a part of the latter.

Abstract: Light from an optical fiber is incident on a frequency dispersion element. The frequency dispersion element disperses the incident light into light beams in different directions according to their frequencies and directs the dispersed light beams to a lens. The lens develops the incident light beams over an xy plane according to their frequencies in a strip-like form. A frequency selective element has pixels arranged in a frequency dispersion direction and brings pixels located at positions corresponding to the frequency to be selected into a reflective state. A light beam selected by the frequency selective element is emitted from an optical fiber through the same path. By changing reflection characteristics of the frequency selective element according to each pixel, optical filter characteristics can be desirably changed so as to achieve change of passband width and frequency shift.

Abstract: Optical waveguides using segmented periodically-spaced high contrast gratings bounding a hollow core propagation region on at least two sides. Incident light is received in a hollow waveguide (HW) region (core) between opposing HCG faces which provide lateral confinement in response to glancing reflections of the incident light beam from high refractive index segments of the HCG as it traverses the core. Embodiments are described for planar waveguides (1D) having a planar core between two planar HCGs, as well as 2D waveguides, such as having rectangular segments of the HCG through which light is propagated. Additionally, other configurations of HCG-HW, including those having arbitrary incidence and azimuth, angled HCG segments, propagation in a direction which is transverse, or alternatively parallel, to the segments of the HCG.

Abstract: Fiber-laser light is Raman shifted to eye-safer wavelengths prior to spectral beam combination, enabling a high-power, eye-safer wavelength directed-energy (DE) system. The output of Ytterbium fiber lasers is not used directly for spectral beam combining. Rather, the power from the Yb fiber lasers is Raman-shifted to longer wavelengths, and these wavelengths are then spectrally beam combined. Raman shifting is most readily accomplished with a “cascaded Raman converter,” in which a series of nested fiber cavities is formed using fiber Bragg gratings.

Abstract: An apparatus includes a waveguide including a core layer having curved edges shaped to reflect light to a focal point, and a grating positioned adjacent to or imbedded in the core layer, wherein at least a portion of the grating is positioned between the curved edges and adjacent to or imbedded in a portion of the core layer that is not traversed by light reflected from the curved edges. A data storage device that includes the apparatus is also provided.

Abstract: An optical dispersion compensator including a first optical device in which light inputted from a first port is outputted from a second port and light inputted from the second port is outputted from a third port, an optical filter type dispersion compensation device that receives light from the second port of the first optical device and compensates wavelength dispersion with respect to the received light, and a second optical device that includes a fourth port to which light is inputted from the optical filter type dispersion compensation device, and in which the light inputted from the fourth port is outputted from a fifth port and light inputted from a sixth port is outputted from the fourth port.

Abstract: An arrayed waveguide grating includes input waveguides, an input slab waveguide, n output waveguides, an output slab waveguide, and an arrayed waveguide. Gaps are formed in the output waveguides other than the output waveguides of both sides of an array of the output waveguides, respectively, such that loss increases toward the central side of the array. Sizes of the gaps in the output waveguides increase toward the central side of the array.

Abstract: An optical wavelength dispersion device includes a first substrate, an input unit formed on the first substrate having a slit for receiving an optical signal, a grating formed on the first substrate for producing a first light beam form the optical signal for outputting, and a second substrate covered on the top of the input unit and the grating, wherein the input unit and the grating are formed from a photo-resist layer by high energy light source exposure.

Abstract: A method and apparatus are provided for attenuating an optical beam. The method includes selecting a level of attenuation to be applied to the optical beam. A pattern of on-state and off-state pixels in a two dimensional spatial light modulator (SLM) is selected such that the pattern will modulate the optical beam to provide the selected level of attenuation. Finally, the optical beam is directed onto the SLM while tile pixels are arranged in the selected pattern. The pattern is periodic along a first axis and symmetric along a second axis along which an intensity distribution of die optical beam extends.

Abstract: A leaky travelling wave array of optical elements provide a solar wavelength rectenna.

Abstract: A device is disclosed. The device contains a first electro-optical waveguide comprising at least one first grating, a second electro-optical waveguide comprising at least one second grating, a plurality of electrodes disposed adjacent to the first grating and configured to impose an electric field through the first electro-optical waveguide to modify spectra of the first grating, a fiber amplifier configured to propagate a laser radiation between the first electro-optical waveguide and the second electro-optical waveguide, and at least two circulators associated with the fiber amplifier and the first electro-optical waveguide and the second electro-optical waveguide and configured to provide unidirectional propagation of the laser radiation along the fiber amplifier.

Abstract: A security system lays out a sensing optical fiber tautly at the perimeter of an area to be secured. The sensing optical fiber has at least one sensing Fiber Bragg Grating (FBG) which is stretched when the sensing optical fiber is stretched by an intruder. The center wavelength of reflection of the stretched sensing FBG shifts towards longer wavelengths. The shifted center wavelength of reflection is detected using a reference FBG with a longer center wavelength of reflection. The sensing optical fiber has a loose buffer coating for isolating the sensing optical fiber and the sensing FBG from nuisance disturbances and noise such as vibrations caused by wind. Trip wires may be attached to the sensing optical fiber for enhancing intruder detection. A cut of the sensing optical fiber may be detected by monitoring the optical power exiting the far end of the sensing optical fiber.

Abstract: A method and system for coupling optical signals into silicon optoelectronic chips are disclosed and may include coupling one or more optical signals into a back surface of one or more of a plurality of CMOS photonic chips comprising photonic, electronic, and optoelectronic devices. The devices may be integrated in a front surface of the chips and optical couplers may receive the optical signals in the front surface of the chips. The optical signals may be coupled into the back surface of the chips via optical fibers and/or optical source assemblies. The optical signals may be coupled to the optical couplers via a light path etched in the chips, which may be refilled with silicon dioxide. The chips may be flip-chip bonded to a packaging substrate. Optical signals may be reflected back to the optical couplers via metal reflectors, which may be integrated in dielectric layers on the chips.

Abstract: A measurement device including a fastener for use in attaching a first member to a second member, in which the fastener has an aperture extending through a length of the fastener, and a first optical fiber located within the aperture, in which the first optical fiber includes at least one fiber Bragg grating sensor. At least a portion of the first optical fiber can be secured within the aperture. A first end of the first optical fiber can be connected to an associated first optical connector and a second end of the first optical fiber can be connected to an associated second optical connector.

Abstract: There is provided a wearable display comprising a light source emitting light of a first wavelength; a first SBG device having a front side and a rear side; first and second transparent plates sandwiching said SBG device; independently switchable transparent electrode elements applied to the opposing surfaces of said transparent plates, a means for spatio-temporally modulating light from the light source to provide image light and a means for coupling the image light into the light guide formed by the two transparent plates and the SBG device. The SBG device comprises a multiplicity of selectively switchable grating regions. The SBG device diffracts image into the pupil of an eye.

Abstract: Regarding an optical pulse reshaping device of CPF type, there are subjects to reduce the number of stages by enhancing a compression efficiency as extremely higher for one stage of the CPF with maintaining a quality of an output pulse as high, and to be able to improve a degree of multiplexing by obtaining an output pulse having a Gaussian function for both of a time waveform therefor and a frequency waveform therefor. By using a normal dispersion HNLF in place of a zero dispersion HNLF, which configures the conventional CPF, it becomes able to overcome the above mentioned subjects. Moreover, it becomes able to reduce the number of fusion splice for a fiber, and to reduce a propagation loss of the CPF, by enhancing the compression efficiency as higher.

Abstract: A bridge intelligent cable system with a built-in fiber grating sensor is provided, which is applied in a cable bearing structure such as a cable-stayed bridge, a suspension bridge, and an arch bridge. The system includes an anchor cup, a wire dividing plate, a connecting cylinder, a fiber grating sensor, and a cable body, in which the fiber grating sensor includes a fiber grating strain sensor and a fiber grating temperature sensor, tail fibers of the fiber grating strain sensor and the fiber grating temperature sensor are led out, the packaged fiber grating strain sensor is fixedly connected to an outer-layer steel wire of the connecting cylinder, the packaged fiber grating temperature sensor is suspended on the steel wire of the connecting cylinder, holes are punched in the wire dividing plate, and a preserved steel pipe is buried in advance in the connecting cylinder and the anchor cup.

Abstract: A method of producing a coated FBG optical fiber involves coating the optical fiber prior to writing the Bragg grating. A system for producing the coated FBG optical fibers includes a high temperature furnace from which to draw the fiber, a coating applicator that may be a carbon coating applicator, a cooling station, and a grating writing station.

Abstract: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

Abstract: Provided is a semiconductor integrated circuit. The semiconductor integrated circuit includes a semiconductor pattern disposed on a substrate and including an optical waveguide part and a pair of recessed portions. The optical waveguide part has a thickness ranging from about 0.05 ?m to about 0.5 ?m. The recessed portions are disposed on both sides of the optical waveguide part and have a thinner thickness than the optical waveguide part. A first doped region and a second doped region are disposed in the recessed portions, respectively. The first and second doped regions are doped with a first conductive type dopant and a second conductive type dopant, respectively. An intrinsic region is formed in at least the optical waveguide part to contact the first and second doped regions.

Abstract: A method and system for providing an optical grating are described. The optical grating is configured for light of a wavelength. The optical grating includes a top cladding, a first plurality of discrete ridges forming a first grating, a core, a second plurality of discrete ridges forming a second grating, and a bottom cladding. The first plurality of discrete ridges are spaced apart by a first pitch. The second plurality of discrete ridges are spaced apart by a second pitch. The core has a top side adjacent to at least a portion of the top cladding and a bottom side. The bottom cladding is adjacent to at least a portion of the bottom side of the core. The second grating resides between the bottom cladding and the core.