Abstract: A diffraction optical waveguide is disclosed, which comprises a grating structure formed on a waveguide substrate. The grating structure comprises a plurality of optical unit structures arranged in an array along a plane; the optical unit structure has a first end and a second end in a first direction parallel to the plane, a distance between the two ends along the first direction is a length L of the optical unit structure; it has a maximum width W perpendicular to the first direction in a predetermined section along the first direction, where 0.3L?W?0.7L, and a central position of the predetermined section is at a predetermined distance d from the first end in the first direction, where d<0.5L; and a width gradually decreases from the predetermined section to both ends, so that a centroid of a cross-section of the optical unit structure is closer to the first end.

Abstract: Examples described herein relate to an optical device with an integrated light-emitting structure to generate light and a waveguide integrated capacitor to monitor light. The light-emitting structure may emit light upon the application of electricity to the optical device. The waveguide integrated capacitor may be formed under the light-emitting structure to monitor the light emitted by the light-emitting structure. The waveguide integrated capacitor includes a waveguide region carrying at least a portion of the light. The waveguide region includes one or more photon absorption sites causing the generation of free charge carriers relative to an intensity of the light confined in the waveguide region resulting in a change in the conductance of the waveguide region.

Abstract: A waveguide based wavelength-tunable laser formed on a semiconductor substrate includes a first reflector from which laser light is output, a second reflector configuring a laser resonator together with the first reflector, a gain portion that is provided between the first reflector and the second reflector, at least two wavelength filters that can adjust wavelength characteristics and adjust a wavelength of the laser light, and a phase adjuster that adjusts an optical path length in the laser resonator, and a waveguide is formed to fold back an optical path by an angle of substantially 180 degrees between the first reflector and the second reflector.

Abstract: An AR glasses device includes a supporting portion, an optical-mechanical assembly, and an adjustment assembly comprising a first adjustment module and a second adjustment module. The optical-mechanical assembly comprises a first optical-mechanical module and a second optical-mechanical module arranged in a second direction. The first optical-mechanical module comprises a first waveguide sheet and a first fixing portion to drive the first waveguide sheet to rotate about the second direction. The second optical-mechanical module comprises a second fixing portion and a second waveguide sheet. The first adjustment module extends through the supporting portion in a first direction and connects the first fixing portion. An arc-shaped groove about the first direction penetrates the supporting portion in the first direction.

Abstract: A coupling system includes an optical fiber configured to carry an optical signal. The coupling system further includes a chip in optical communication with the optical fiber. The chip includes a substrate. The chip further includes a grating on a first side of the substrate, wherein the grating is configured to receive the optical signal. The chip further includes an interconnect structure over the grating on the first side of the substrate, wherein the interconnect structure defines a cavity aligned with the grating. The chip further includes a first polysilicon layer on a second side of the substrate, wherein the second side of the substrate is opposite to the first side of the substrate.

Abstract: With a wavelength conversion device based on a nonlinear optical effect, when arrayed waveguides including an intended nonlinear waveguide are fabricated, unwanted slab waveguides are inevitably formed. The slab waveguides can cause an erroneous measurement in the selection of a waveguide having desired characteristics from the arrayed waveguides. The erroneous measurement can lead to redoing steps for fabricating the wavelength conversion device and a decrease in the yield and inhibit the evaluation of the characteristics in selection of the waveguide and the subsequent fabrication of the wavelength conversion device from being efficiently performed. A wavelength conversion device according to the present invention includes a plurality of waveguides formed on a substrate, and a plurality of slab waveguides that are arranged substantially in parallel with and spaced apart from the plurality of waveguides, and each of the slab waveguides has a grating structure that reflects light of a particular wavelength.

Abstract: An optical system provides two-stage expansion of an input optical aperture for a display based on a light-guide optical element. A first expansion is achieved using two distinct sets of mutually-parallel partially-reflecting surfaces, each set handing a different part of an overall field-of-view presented to the eye. In some cases, a single image projector provides image illumination to two sets of facets that are integrated into the LOE. In other cases, two separate projectors deliver image illumination corresponding to two different parts of the field-of-view to their respective sets of facets.

Abstract: An optical system performs a method for measuring an acoustic signal in a wellbore. The optical system includes a light source, an optical fiber and a detector. The light source generates a light pulse. The optical fiber has a first end for receiving the light pulse from the light source and a plurality of enhancement scatterers spaced along a length of the optical fiber for reflecting the light pulse. A longitudinal density of the enhancement scatterers increases with a distance from the first end to increase a signal enhancement generated by the enhancement scatterers distal from the first end. The detector is at the first end of the optical fiber and measures a reflection of the light pulse at the enhancement scatterers to determine the acoustic signal.

Abstract: The present disclosure relates to systems and methods relating to the fabrication of light guide elements. An example system includes an optical component configured to direct light emitted by a light source to illuminate a photoresist material at one or more desired angles so as to expose an angled structure in the photoresist material. The photoresist material overlays at least a portion of a first surface of a substrate. The optical component includes a container containing a light-coupling material that is selected based in part on the one or more desired angles. The system also includes a reflective surface arranged to reflect at least a first portion of the emitted light to illuminate the photoresist material at the one or more desired angles.

Abstract: A method for fabricating a nano-structure includes: providing a phase mask having an uneven lattice structure to contact a photoresist film; exposing the photoresist film to a light through the phase mask such that the light is obliquely incident on a surface of the photoresist film; and developing the photoresist film to form a nano-structure.

Abstract: The present disclosure provides for two-dimensional mode matching by receiving an optical signal traveling in a first direction; and scattering the optical signal according lto a scattering strength that progressively changes in the first direction. In various embodiments, the scattering strength progressively changes by increasing or decreasing in the first direction. A plurality of scatterers disposed in a path of the optical signal change in widths that progressively increase or decrease along the first direction. In various embodiments, a second optical signal is received in the grating coupler from a second direction; and is scattered into a surface of a photonic chip via a grating coupler. In some embodiments, the second direction is perpendicular to the first direction.

Abstract: The present disclosure relates to a metasurface structural body or the like having a structure for achieving desired optical characteristics. The metasurface structural body includes a base member having a first surface and a second surface opposing each other, and a plurality of antennas as a plurality of fine structures arranged along the first surface. The base member has a base portion and an adjacent portion. The antennas each has a first refractive index and an antenna end surface constituting a part of the first surface. The adjacent portion is provided such that a part thereof is positioned between the antennas, the adjacent portion having a second refractive index different from the first refractive index and an adjacent-portion end surface constituting a remaining part of the first surface. The antenna end surfaces and the adjacent-portion end surface form a flat surface as the first surface.

Abstract: An optical device has a light-transmitting substrate, an optical coupling-out configuration, and an optical arrangement. The light-transmitting substrate has at least two major surfaces and guides light by internal reflection between the major surfaces. The optical coupling-out configuration couples the light, guided by internal reflection, out of the light-transmitting substrate toward an eye of a viewer. The optical arrangement is associated with at least one of the two major surfaces, and has a first optical element and a second optical element. The optical elements are optically coupled to each other to define an interface region associated with at least a portion of the coupling-out configuration. The interface region deflects light rays that emanate from an external scene that are incident to the optical arrangement at a given range of incident angles.

Abstract: A packaged transmitter device includes a base member comprising a planar part mounted with a thermoelectric cooler, a transmitter, and a coupling lens assembly, and an assembling part connected to one side of the planar part. The device further includes a circuit board bended to have a first end region and a second end region being raised to a higher level. The first end region disposed on a top surface of the planar part includes multiple electrical connection patches respectively connected to the thermoelectric and the transmitter. The second end region includes an electrical port for external connection. Additionally, the device includes a cover member disposed over the planar part. Furthermore, the device includes a cylindrical member installed to the assembling part for enclosing an isolator aligned to the coupling lens assembly along its axis and connected to a fiber to couple optical signal from the transmitter to the fiber.

Abstract: Techniques relating to an improved optical waveguide are described. The optical waveguide includes an upper and lower waveguide that each comprise a first and second layer, in which photons are transferred from the lower waveguide to the upper waveguide. A structured subwavelength coupling region is included, for example, in the first upper waveguide layer. The fill factor of the subwavelength grating coupling region is increased in the direction of light propagation to increase the index of refraction of the structured subwavelength coupling region and therefore improve photon transfer from the lower waveguide. Additionally, the width of the optical waveguide (at least along the structured subwavelength coupling region) remains constant as the fill factor increases.

Abstract: Methods and apparatus for performing quantum annealing using a quantum system. In one aspect, a method includes controlling the quantum system such that a total Hamiltonian characterizing the quantum system evolves from an initial quantum Hamiltonian to a problem quantum Hamiltonian, wherein controlling the quantum system comprises applying an inhomogeneous driving field to the quantum system to drive the quantum system across a quantum phase transition.

Abstract: Lidar detection device based on a lens and an integrated beam transceiver, comprising a laser, a coupling fiber, a substrate, an input waveguide, a connection waveguide, a 1×N optical switch, a switch electrical interface, N switch output waveguides, N transceiving units, an off-chip processor and a lens, wherein N is a positive integer above 2. The invention can realize three-dimensional detection of a target, and the invention has the characteristics of two-dimensional beam steering independent of wavelength switching, low control complexity, low electric power consumption, receiving and emitting monolithic integration and high receiving efficiency, and being compatible with two laser ranging functions of ToF and FMCW.

Abstract: An optical transceiver includes a silicon photonics substrate, transmitter circuitry, and receiver circuitry that are heterogeneously integrated. The transmitter circuitry includes a plurality of laser devices formed on the silicon photonics substrate, each of the plurality of laser devices configured to generate a respective laser light, a plurality of modulators formed on the silicon photonics substrate, each of the plurality of modulators configured to modulate the laser lights based on driver signals and output, from the silicon photonics substrate, the modulated laser lights, and a driver formed on the silicon photonics substrate and configured to generate the driver signals.

Abstract: Embodiments presented in this disclosure generally relate to an optical device having a grating coupler for redirection of optical signals. One embodiment includes a grating coupler. The grating coupler generally includes a waveguide layer, a thickness of a waveguide layer portion of the waveguide layer being tapered, the thickness defining a direction, and a grating layer disposed above the waveguide layer and perpendicular to the direction where at least a grating layer portion of the grating layer overlaps the waveguide layer portion of the waveguide layer along the direction. Some embodiments are directed to grating coupler implemented with material layers above and a reflector layer below a grating layer, facilitating redirection and confinement of light that improves coupling loss and bandwidth. The material layers and reflector layer above and below the grating layer may be implemented with or without the waveguide layer being tapered.

Abstract: A photonic device and a continuous-wave THz signal generator using such photonic device. The photonic device includes an input waveguide arranged to receive input waves of at least two input frequencies and to generate photons at an output frequency associated with the at least two input frequencies; an output waveguide coupled to the input waveguide and arranged to collect the generated photons at the output frequency; wherein the output waveguide is further arranged to facilitate an amplification of the generated photons as the generated photons propagates along the output waveguide and arranged to output an amplified signal at the output frequency.

Abstract: The present disclosure describes an optical waveguide provided with an incident side reflection film and an emission side reflection film to resonate light incident via the incident side reflection film and formed to penetrate from the incident side reflection film to the emission side reflection film for propagating resonated light. The disclosure also includes a substrate to which the optical waveguide is formed from a top surface thereof and a first protection member and a second protection member formed with a material corresponding to a material of the substrate, wherein the first protection member and the second protection member are arranged on the optical waveguide such that one end facet of the first protection member forms an identical plane with a first end facet of the substrate including an optical incident end.

Abstract: A system and method for automated laser ablation includes an end effector for performing laser ablation at a location with restricted access. The systems and methods of the present disclosure specifically provide for a miniature laser end effector which may be inserted through a port or bore in order to ablate the surface of an internal component of a complex assembly. In several embodiments of the present subject matter, the end effector is mounted on a machine and coupled to a laser system.

Abstract: An apparatus having a segmented optical modulator includes an optical waveguide having three or more segments. Each of three or more optical modulators includes a corresponding waveguide segment and is configured to apply an optical modulation that is proportional to the length of the segment. Three or more electrical contacts receive respective bit values of binary values. Each binary value includes at least three bit values including a least significant bit (LSB) bit value, a most significant bit (MSB) bit value, and at least one intermediate bit (IB) bit value between the LSB bit value and the MSB bit value. At least one waveguide segment of a corresponding optical modulator receiving an LSB bit value is positioned between a first waveguide segment of a corresponding optical modulator receiving an MSB bit value and a second waveguide segment of a corresponding optical modulator receiving an IB bit value.

Abstract: Described are various configurations of optical structures having asymmetric-width waveguides. A photodetector can include parallel waveguides that have different widths, which can be connected via passive waveguide. One or more light absorbing regions can be proximate to the waveguides to absorb light propagating through one or more of the parallel waveguides. Multiple photodetectors having asymmetric width waveguides can operate to transduce light in different modes in a polarization diversity optical receiver.

Abstract: Display devices include waveguides with in-coupling optical elements that mitigate re-bounce of in-coupled light to improve overall in-coupling efficiency and/or uniformity. A waveguide receives light from a light source and/or projection optics and includes an in-coupling optical element that in-couples the received light to propagate by total internal reflection in a propagation direction within the waveguide. Once in-coupled into the waveguide the light may undergo re-bounce, in which the light reflects off a waveguide surface and, after the reflection, strikes the in-coupling optical element. Upon striking the in-coupling optical element, the light may be partially absorbed and/or out-coupled by the optical element, thereby effectively reducing the amount of in-coupled light propagating through the waveguide.

Abstract: Systems, devices, and methods for for exit pupil expansion in a curved lens with embedded light guide are described. Exit pupil expansion in a curved lens may be achieved with a light guide comprising an outcoupler with minimized second order diffraction, where the outcoupler applies an optical power to outcoupled light.

Abstract: Embodiments of the disclosure provide an optical antenna for a photonic integrated circuit (PIC). The optical antenna includes a semiconductor waveguide on a semiconductor layer. The semiconductor waveguide includes a first vertical sidewall over the semiconductor layer over the semiconductor layer. A plurality of grating protrusions extends horizontally from the first vertical sidewall of the semiconductor waveguide.

Abstract: The invention relates to a waveguide and a polarisation splitter based on said waveguide, in which a rotation of an angle greater than zero is applied to a plurality of sections of a core material and a plurality of sections of a covering material, thereby achieving an independent control of the refractive indices of a zero-order transverse electric mode and a zero-order transverse magnetic mode. This document also describes a manufacturing method of said waveguide which allows the birefringence of the light that passes through the waveguide.

Abstract: A method of forming patterned features on a substrate is provided. The method includes positioning a plurality of masks arranged in a mask layout over a substrate. The substrate is positioned in a first plane and the plurality of masks are positioned in a second plane, the plurality of masks in the mask layout have edges that each extend parallel to the first plane and parallel or perpendicular to an alignment feature on the substrate, the substrate includes a plurality of areas configured to be patterned by energy directed through the masks arranged in the mask layout. The method further includes directing energy towards the plurality of areas through the plurality of masks arranged in the mask layout over the substrate to form a plurality of patterned features in each of the plurality of areas.

Abstract: A light flux diameter expanding element includes a light guiding plate with a light input face and a light output face, and with a thickness of 0.2 mm to 0.8 mm; a diffraction grating on the input side; and a diffraction grating on the output side, and is provided so as to have the same grating period as that of the diffraction grating on the input side, in which a forming region of the diffraction grating on the input side is smaller than that of the output side, and a grating period of the diffraction grating on the input side is a period in which a small diffraction angle in diffraction angles of +1-st order diffracted light and ?1-st order diffracted light, which are diffracted in the diffraction grating on the input side, in the light guiding plate becomes larger than a critical angle of the light guiding plate.

Abstract: An augmented reality display system includes a pair of variable focus lens elements that sandwich a waveguide stack. One of the lens elements is positioned between the waveguide stack and a user's eye to correct for refractive errors in the focusing of light projected from the waveguide stack to that eye. The lens elements may also be configured to provide appropriate optical power to place displayed virtual content on a desired depth plane. The other lens element is between the ambient environment and the waveguide stack, and is configured to provide optical power to compensate for aberrations in the transmission of ambient light through the waveguide stack and the lens element closest to the eye. In addition, an eye-tracking system monitors the vergence of the user's eyes and automatically and continuously adjusts the optical powers of the pair of lens elements based on the determined vergence of those eyes.

Abstract: A method of optimizing the coupling to an optical fiber, including: generating a femtosecond laser pulse; directing a focus of the laser pulse to a longitudinal depth in the region beneath the endface of the optical fiber to generate microvoids; adjusting the intensity of the laser pulse at different depths, such that a refractive index profile is created in the region beneath the endface of the optical fiber.

Abstract: A waveguide apparatus, comprises: disposed in at least one layer: an input coupler; a first fold grating; a second fold grating; an output coupler; and a source of light optically coupled to the waveguide providing at least first and second polarizations of the light and at least one wavelength. The input coupler is configured to cause the first polarization light to travel along a first total internal reflection (TIR) path and the second polarization light to travel along a second TIR path.

Abstract: A silicon nitride phased array chip based on a suspended waveguide structure, which includes a silicon nitride waveguide area and a suspended waveguide area. The silicon nitride waveguide area includes a silicon substrate, a silicon dioxide buffer layer, a silicon dioxide cladding layer and a silicon nitride waveguide-based core layer. The silicon nitride waveguide-based core layer includes an optical splitter unit, a first curved waveguide, a thermo-optic phase shifter and a spot-size converter. The suspended waveguide area includes a second curved waveguide and an array grating antenna.

Abstract: A connector assembly includes a connector, an optical waveguide and a circuit board having a through-hole and a transmitter/receiver configured to transmit and/or receive light signals. The connector is interlockingly and releasably connected to the circuit board via a fastening element which is passed through the through-hole and connected to the circuit board. The connector has a receiving chamber which at least partially borders the transmitter/receiver. A lens unit is disposed in the receiving chamber and light-conductively connects the transmitter/receiver to the optical waveguide. A locking element is movably disposed on the connector. The locking element is disposed at least partially within the receiving chamber and secures the lens unit in the receiving chamber. The locking element is movable into a final latched position in which the locking element extends at least partially into the through-hole and blocks release of the fastening element from the circuit board.

Abstract: Provided are: a light guide element that includes an intermediate diffraction element to expand exit pupil such that a light utilization efficiency is high and a decrease in the brightness of an image to be displayed can be suppressed; and an image display apparatus.

Abstract: Multi-clad optical fiber cladding light stripper (CLS) comprising an inner cladding with one or more recessed surface regions to remove light propagating within the inner cladding. A CLS may comprise such recessed surface regions along two or more azimuthal angles about the fiber axis, for example to improve stripping efficiency. One or more dimensions, or spatial distribution, of the recessed surface regions may be randomized, for example to improve stripping uniformity across a multiplicity of modes propagating within a cladding. Adjacent recessed surface regions may abut, for example, end-to-end, as segments of a recess that occupies a majority, or even an entirety, of the length of a fiber surrounded by a heat sink. One or more dimensions, or angular position, of individual ones of the abutted recessed surface regions may vary, according to a regular or irregular pattern.

Abstract: An optoelectronic device. The optoelectronic device comprising: a rib waveguide provided on a substrate of the device, the rib waveguide comprising a ridge portion and a slab portion; a heater, disposed within the slab portion; a thermally isolating trench, adjacent to the rib waveguide, and extending into the substrate of the device; and a thermally isolating cavity within the substrate, which is directly connected to the thermally isolating trench, and which extends across at least a part of a width of the rib waveguide between the rib waveguide and the substrate.

Abstract: A modular assembly for opto-electronic systems has a substrate on which various photonic integrated circuit (PIC) chips and electronic integrated circuit (EIC) chips are mounted. One or more waveguide (WG) chips mounted on the substrate align the optical communication between the PIC chips and fiber blocks for optical fibers. Preconfigured electrical connections in the substrate allow the PIC and EIC chips to communicate with one another and to communicate with solder bumps on the substrate for integration of the modular assembly with other electronic components.

Abstract: A tunable laser includes a reflective semiconductor optical amplifier (SOA), a grating codirectional coupler, and a reflective microring resonator. The grating codirectional coupler and the reflective microring resonator are both formed on a silicon base. An anti-reflection film is disposed on a first end surface of the reflective SOA, and the first end surface is an end surface, coupled to a first waveguide of the grating codirectional coupler, of the reflective SOA. A second waveguide of the grating codirectional coupler is coupled to the first waveguide, a first grating is disposed on the first waveguide, a second grating disposed opposite to the first grating is disposed on the second waveguide, and the first grating and the second grating constitute a narrow-band pass filter. The second waveguide is connected to the reflective microring resonator.

Abstract: An internal laser component of an optical device comprises: a waveguide that defines a guided mode of a first optical wave characterized by a first propagation constant associated with a first effective refractive index. An optical antenna grating comprises: a waveguide that defines a guided mode of a second optical wave characterized by a second propagation constant associated with a second effective refractive index, and a grating structure configured to emit a portion of the second optical wave in a selected direction. The internal laser component and the optical antenna grating are configured to provide a relationship between the first effective refractive index and the second effective refractive index such that the selected direction is substantially insensitive to a change in a temperature of a thermal environment in which the internal laser component and the optical antenna grating are thermally coupled.

Abstract: A method of wheel encoder to camera calibration, including receiving a LiDAR (Light Detection and Ranging) signal, receiving a camera signal, receiving a wheel encoder signal, calibrating the camera signal to the LiDAR signal, calibrating the wheel encoder signal to the LiDAR signal and calibrating the camera signal to the wheel encoder signal based on the calibration of the camera signal to the LiDAR signal and the wheel encoder signal to the LiDAR signal.

Abstract: An optical system is provided including a photonic integrated circuit and an optical lens system. The photonic integrated circuit includes an emission interface surface and a spatial array of apertures. The spatial array of apertures has a high numerical aperture (NA) of greater than 0.2 and includes a plurality of apertures spatially distributed across the interface surface. The optical lens system interfaces the photonic integrated circuit with free space by: receiving emitted light from the spatial array of apertures and altering a trajectory of the emitted light into the free space and receiving returning light from the free space and altering a trajectory of the returning light, such that the returning light is received by the spatial array of apertures.

Abstract: An optical element includes a substrate, an intermediate layer, a topmost layer, and a contiguous multitude of recessed and non-recessed areal regions. The intermediate layer is formed over a top surface of the substrate and has a refractive index nI. The topmost layer is formed directly on the intermediate layer and has a refractive index nT where nT?nI. The intermediate and topmost layers are substantially transparent over an operational wavelength range that includes a design wavelength ?0. A subset of areal regions has a largest transverse dimension less than about ?0. Each non-recessed areal region includes corresponding portions of the intermediate and topmost layers. Each recessed areal region extends entirely through the topmost layer and at least partly through the intermediate layer. A fill medium fills the recessed areal regions. The areal regions are variously sized and distributed transversely across the optical element.

Abstract: In the wavelength selective fiber optic switch, an optical fiber with a portion of cladding removed defines a window facilitating access to the radially evanescent field present when optical power is propagating through the optical fiber, defining a first transmission path. The cladding removed optical fiber, a secondary optical waveguide, and a grating structure form a grating assisted coupler. An adjustable positioning fixture changes the relative spacing of the fiber core, grating, and output waveguide between a decoupled position and a coupled position. The switch operates, in the decoupled position, to allow optical power to propagate unperturbed through the first transmission path, including optical power at said optical wavelength, and in the coupled position, to extract and reroute optical power at the optical wavelength to propagate through the second transmission path, while leaving unperturbed other wavelengths propagating through the first transmission path.

Abstract: An optical fiber sensor includes an optical fiber. The optical fiber includes a cladding having a cladding refractive index, and a plurality of fiber cores embedded in the cladding and extending along a longitudinal axis of the optical fiber. The plurality of fiber cores include a first subset of at least one first fiber core and a second subset of at least one second fiber core. The at least one first fiber core has a first core refractive index different from the cladding refractive index and a first core radius in a direction transverse to the longitudinal axis. The at least one second fiber core has a second core refractive index different from the cladding refractive index and a second core radius transverse to the longitudinal axis. The second core refractive index and the second core radius differ from the first core refractive index and the first core radius such that a temperature sensitivity of the at least one second fiber core differs from the temperature sensitivity of the first fiber core.

Abstract: An optical waveguide device for use in a head up display. The waveguide device provides pupil expansion in two dimensions. The waveguide device comprise a primary waveguide and a secondary waveguide, the secondary waveguide being positioned on a face of the primary waveguide. The secondary waveguide has a diffraction grating on a face opposite to the face which contacts the primary waveguide. The diffraction grating diffracts light into more than one diffraction order. Rays diffracted into a non-zero order are trapped in the secondary waveguide by total internal reflection.

Abstract: An optical device for coupling light propagating between a waveguide and an optical transmission component is provided. The optical device includes a taper portion and a grating portion. The taper portion is disposed between the grating portion and the waveguide. The grating portion includes rows of grating patterns. A first size of a first grating pattern in a first row of grating patterns is larger than a second size of a second grating pattern in a second row of grating patterns. A first distance between the first row of grating patterns and the waveguide is less than a second distance between the second row of grating patterns and the waveguide.

Abstract: Systems and methods for reducing the variation in the power of optical signals transmitted in an upstream direction, at the inputs of an active combiner in an RFoG CATV architecture preferably configured to reduce optical beat interference, so as to increase the dynamic range of a laser in the active combiner.

Abstract: Systems and methods for identifying a device are described. In an example, a processor can receive a first signal having a first waveform encoding data. The processor can extract the data from the first signal. The processor can determine a transformation being used to encode the data in the first waveform. The processor can generate a second signal using the determined transformation to encode the data in a second waveform. The processor can determine a difference between the first waveform and the second waveform. The processor can identify a device as a candidate device that sent the first signal, based on the determined difference.