Abstract: A fault detection apparatus includes: a transmitter that transmits a first optical signal through an optical transmission line; a receiver that receives, in response to the transmission of the first optical signal, a second optical signal from the line, and measures the reception level of the second optical signal; and a control unit that specifies a section where the second optical signal corresponding to the first optical signal was generated, calculates an optical level corresponding to a loss in said section on the basis of the reception level, determines that a first fault has occurred in the section when the optical level in the section has changed from a first reference level by a first threshold or more, sets a second reference level and a second threshold after occurrence of the first fault, and determines occurrence of a second fault.

Abstract: Provided is an optical switch element capable of adjusting an output strength of light output from an optical switch to a fixed level.

Abstract: A thermally tunable microresonator device with enhanced thermal confinement for greater efficiency is provided. A thermal confinement structure is electrically connected in series with the heater element used for tuning the microresonator. The heater element is conformed in a circular arc concentric with the microresonator, the thermal confinement structure comprises two or more tiers, and each tier comprises at least one metal trace conformed in a circular arc concentric with the microresonator.

Abstract: Various embodiments of the present disclosure are directed towards an integrated chip including a waveguide and a heater structure. The waveguide is disposed on a substrate and comprises an active region that extends continuously along a first distance. The heater structure overlies the waveguide. The heater structure comprises a conductive structure over the active region and a vertical structure disposed between the conductive structure and the substrate. The vertical structure comprises a conductive upper vertical segment and a lower vertical segment. The conductive structure and the conductive upper vertical segment continuously laterally extend across a second distance that is greater than or equal to the first distance. The first distance is greater than a width of the conductive structure.

Abstract: A nonlinear converter may comprise: alternating layers of a dielectric material and a metal material; a first refractive index of the nonlinear converter for a first wavelength (i.e., input wavelength or pump wavelength) between 207 nm and 237 nm, the first refractive index being less than 0.5, the first refractive index corresponding to metal fill ratio; and a second refractive index of the nonlinear converter for a second wavelength (i.e., output wavelength or SHG wavelength), the second wavelength being approximately double the first wavelength, the second refractive index corresponding to the metal fill ratio.

Abstract: An optical circuit includes one or more input waveguides, a plurality of output waveguides, and a reflector structure. At least a portion of the reflector structure forms an interface with the one or more input waveguides. The portion of the reflector structure has a smaller refractive index than the one or more input waveguides. An electrical circuit is electrically coupled to the optical circuit. The electrical circuit generates and sends different electrical signals to the reflector structure. In response to the reflector structure receiving the different electrical signals, a carrier concentration level at or near the interface or a temperature at or near the interface changes, such that incident radiation received from the one or more input waveguides is tunably reflected by the reflector structure into a targeted output waveguide of the plurality of output waveguides.

Abstract: A splitter. In some embodiments, the splitter includes an input waveguide; a first output waveguide; a second output waveguide; a first internal waveguide, connected to the input waveguide and to the first output waveguide, and a second internal waveguide, coupled to the first internal waveguide and connected to the second output waveguide. The splitter may be configured, when fed, at the input waveguide, power in a fundamental mode of the input waveguide or power in a first order spatial mode of the input waveguide: to transmit at least 80% of the power in the fundamental mode to the first output waveguide, and to transmit at least 80% of the power in the first order spatial mode to the second output waveguide.

Abstract: A fringe projector apparatus includes: a phase modulator having a first waveguide, a second waveguide, and a plurality of heaters including a first heater and a second heater, wherein the first and second waveguides and the plurality of heaters are provided on a single substrate, and wherein the first heater heats the first waveguide and the second heater heats a position away from the first waveguide; a light source that generates a light beam to be input to the first waveguide and the second waveguide; and a controller that controls a phase difference between the first waveguide and the second waveguide by changing an electric power consumption of the first heater under a condition that a total electric power consumption of the plurality of heaters is constant.

Abstract: It is an object of the present invention to provide a polymerizable compound having a good liquid crystal property, a good alignment property, sufficient solubility in solvents, high preservation stability in a solution state, and high optical stability; a composition including the polymerizable compound; a polymer produced by polymerizing the polymerizable compound, such as a resin produced using the polymerizable compound; an optically anisotropic body including the polymer; and a liquid crystal display element and an organic EL device that include the optically anisotropic body. As a result of conducting intensive studies in order to achieve the above object, the compound represented by General Formula (I) is developed.

Abstract: A PhC all-optical multistep-delay self-OR-transformation logic gate including an optical switch unit, a PhC structure unit, a reference-light, a memory or delayer, a D-type flip-flop unit and a wave absorbing load; a logic signal X is connected to the input port of a two-branch waveguide whose two output ports are respectively connected with the input port of the memory and the logic-signal input port of the optical switch unit; the output port of the memory is connected with the delay-signal input port of the optical switch unit; the reference-light source is connected with the reference-light input port of the optical switch unit whose three intermediate-signal output ports are respectively connected with the first and second intermediate-signal input ports of the PhC structure unit and the wave absorbing load; and the output port of the PhC structure unit is connected with the D-signal input port of the D-type flip-flop unit.

Abstract: A slider configured for heat-assisted magnetic recording has an upper surface, an opposing air bearing surface (ABS), and a body defined between the upper surface and the ABS. The slider comprises a write pole and a near-field transducer (NFT) at or near the ABS. An optical waveguide is configured to receive light from a laser source and comprises a first cladding layer, a second cladding layer, and a core between the first and second cladding layers. The core has a width, a length, and a longitudinal axis oriented along the length of the core. A bolometer is situated within the body of the slider at a location that receives at least some of the light communicated along the waveguide used during a writing operation. The bolometer is spaced apart from the core and comprises a longitudinal axis that is oriented substantially parallel to the longitudinal axis of the core.

Abstract: In one aspect, a device for generating triplet photons is disclosed, which includes a waveguide extending from a proximal end for receiving pump radiation to a distal end through which triplet photons generated via nonlinear interaction of the pump radiation with the waveguide exit the waveguide, where the waveguide is configured such that the triplet photons generated within the waveguide reach its distal end at a rate in a range of about 0.05 triplet photons/second/mW and 0.3 triplet photons/second/mW, e.g., in a range of about 0.1 triplet photons/second/mW to about 0.2 triplet photons/second/mW.

Abstract: The present teachings are generally directed to devices and methods for triplet photons generations, and in particular to on-chip integrated sources for generating direct triplet entangled photons.

Abstract: The present invention relates to a total reflection type optical switch using polymer insertion type silica optical waveguides and a manufacturing method thereof. The total reflection type optical switch forms a trench in an intersecting point of the silica optical waveguides having two optic routes, and inserts a polymer into the trench. A total reflection type optical switch has a heater which heats the polymer. The polymer is made of thermo-optic material, and totally reflects an optical signal as a refraction index falls when heated by the heater. In addition, when not heated by the heater, the polymer transilluminates the optical signal. When the polymer is made of electric-optic material, the total reflection type optical switch may have upper and lower electrodes for applying an electric field in the polymer instead of the heater.

Abstract: Light escaping from an optical path, for example via Raman or Rayleigh scattering, can provide information about how light flows in the path, about the optical path, or about matter disposed in the optical path. The path can be a waveguide, an optical channel, or a fiber that may be attached to or integrated with a substrate, for example in a passive or active planar lightguide/lightwave circuit, photonic integrated circuit, semiconductor laser, or optoelectronic element. The escaped light can be color-shifted with respect to the primary light flowing along the path. The escaped light can leave the path at an angle that facilitates detection. Processing or analyzing the scattered light, for example with support of a computing device, can help evaluate the path and/or assess a light intensity pattern thereof, for example to aid design, engineering, testing, qualification, troubleshooting, inspection, manufacturing, etc.

Abstract: A tunable Radio Frequency (RF) filter device includes a tunable optical source configured to generate an optical carrier signal, and a modulator coupled to the tunable optical source and configured to modulate the optical carrier signal with an RF input signal. The tunable RF filter device may also include first and second optical waveguides coupled to the modulator and having first and second dispersion slopes of opposite sign, and an optical-to-electrical converter coupled to the first and second optical waveguides and configured to generate an RF output signal with a frequency notch therein based upon the tunable optical source.

Abstract: An object of the present invention is to realize an optical gate switch of a monolithic integration type which can avoid problems of losses caused by light coupling of a phase modulation unit to a interferometer optical circuit unit, and can be minimized by integration. The optical gate switch according to the present invention includes an optical waveguide wafer in which a quantum well having a phase modulation effect which is generated by an intersubband transition is set as a core layer; a Michelson interferometer formed on the optical waveguide wafer; and a variable light intensity attenuation unit adjusting a light balance of an interferometer in one of reflection side arms of the Michelson interferometer reflection.

Abstract: A method to align an optical device optically with an interference device is disclosed. The method includes steps of: selecting one of arm waveguides, biasing rest of arm waveguides to cause optical absorption thereat, and aligning the optical device optically with the selected arm waveguide.

Abstract: According to one embodiment of the invention, a plasmonic device has a beam splitter adapted to split a surface-plasmon (SP) input beam into first and second SP beams and direct them along first and second propagation paths, respectively. One of the propagation paths has a plasmonic-beam interaction region adapted to controllably change the phase of the corresponding split beam within that interaction region in response to an SP control signal applied thereto. The plasmonic device further has an SP beam mixer adapted to receive the first and second beams from their respective propagation paths and to mix them to produce an SP output signal. In various configurations, the plasmonic device can operate as a plasmonic-signal amplifier, a plasmonic-beam router, a 1×2 plasmonic-beam switch, and/or a plasmonic modulator.

Abstract: A tunable Radio Frequency (RF) filter device includes a tunable optical source generating an optical carrier signal, and a modulator coupled to the tunable optical source and modulating the optical carrier signal with an RF input signal. The tunable RF filter device may include first and second optical waveguide paths coupled to the modulator and having first and second dispersion slopes of opposite sign from each other, one or more of the first and second optical waveguide paths comprising an optical splitter and combiner pair therein, and an optical-to-electrical converter coupled to the first and second optical waveguide paths and generating an RF output signal with a frequency notch therein based upon the tunable optical source.

Abstract: Compact laser systems are disclosed which include ultrafast laser sources in combination with nonlinear crystals or waveguides. In some implementations fiber based mid-IR sources producing very short pulses and/or mid-IR sources based on a mode locked fiber lasers are utilized. A difference frequency generator receives outputs from the ultrafast sources, and generates an output including a difference frequency. The output power from the difference frequency generator can further be enhanced via the implementation of large core dispersion shifted fibers. Exemplary applications of the compact, high brightness mid-IR light sources include medical applications, spectroscopy, ranging, sensing and metrology.

Abstract: A tunable Radio Frequency (RF) filter device includes a tunable optical source configured to generate an optical carrier signal, and a modulator coupled to the tunable optical source and configured to modulate the optical carrier signal with an RF input signal. The tunable RF filter device may also include first and second optical waveguides coupled to the modulator and having first and second dispersion slopes of opposite sign, and an optical-to-electrical converter coupled to the first and second optical waveguides and configured to generate an RF output signal with a frequency notch therein based upon the tunable optical source.

Abstract: Embodiments of the present invention generally relate to optical mode conversion by nonlinear effects. More specifically, embodiments of the present invention relate to nonlinear mode conversion utilizing intermodal four-wave mixing to convert light between modes having different wavelengths for complex applications. In one embodiment of the present invention, a fiber comprises an input end for receiving light in a first mode at a first wavelength, and an output end for outputting light in a desired second mode at a desired second wavelength, wherein the first wavelength and the second wavelength are not the same. In many embodiments, the fiber comprises a higher-order mode fiber.

Abstract: An apparatus for optical signal detection may include a housing in which a channel may be defined to receive an optical fiber in a bent configuration. The channel may have a predetermined radius of curvature to cause optical energy to escape from the fiber when an optical signal is being conveyed in the fiber and be detected at a photodetector arranged at the predetermined radius of curvature.

Abstract: Some embodiments of the disclosed subject matter provide systems, devices, and methods for tuning resonant wavelengths of an optical resonator. Some embodiments of the disclosed subject matter provide systems, devices, and methods for tuning dispersion properties of photonic crystal waveguides. In some embodiments, methods for tuning a resonant wavelength of an optical resonator are provided, the methods including: providing an optical resonator having a surface; determining an initial resonant wavelength emitted by the optical resonator in response to an electromagnetic radiation input; determining a number of layers of dielectric material based on a difference between the initial resonant wavelength and a target resonant wavelength and a predetermined tuning characteristic; and applying the determined number of layers of dielectric material to the surface of the optical resonator to tune the initial resonant wavelength to a tuned resonant wavelength.

Abstract: The present invention provides an optical 90-degree hybrid circuit for reducing wavelength dependency of an IQ phase difference. An optical 90-degree hybrid circuit according to the present invention comprises a first demultiplexing optical coupler including a first and second input port, a second demultiplexing optical coupler including a third and fourth input port, first and second arm waveguides connected to the first and second input port, each having the same length, a third and fourth arm waveguides connected to the third and fourth input port, each having the same length, a 90-degree phase shift section installed in one of the first to fourth arm waveguides, a first optical coupler connected to the first and third arm waveguide, and a second optical coupler connected to the second and fourth arm waveguide, the light is inputted into the first and fourth input port or into the second and third input port.

Abstract: Consistent with the present disclosure an optical filter is provided that preferably includes a plurality of looped or ring-shaped waveguides provided on a substrate which are coupled to one another by tunable couplers. Portions of each waveguide constitute part of each tunable coupler, which may include, for example, a Mach-Zehnder interferometer. A heater may be thermally coupled to one or both arms of the Mach-Zehnder interferometer, to thereby adjust an amount of optical coupling between adjacent looped waveguides. The filter bandwidth (i.e., the spectral width of the passband), which, as noted above, is related to such coupling, can thus also be tuned or varied. Additional heaters may be provided to tune the center wavelength of the passband so that a filter having both a variable passband spectral width and center wavelength can be obtained.

Abstract: The present invention is a method and an apparatus for dynamic manipulation and dispersion in photonic crystal devices. In one embodiment, a photonic crystal structure comprises a substrate having a plurality of apertures formed therethrough, a waveguide formed by “removing” a row of apertures, and a plurality of pairs of lateral electrical contacts, the lateral electrical contact pairs extending along the length of the waveguide in a spaced-apart manner. The lateral electrical contact pairs facilitate local manipulation of the photonic crystal structure's refractive index. Thus, optical signals of different wavelengths that propagate through the photonic crystal structure can be dynamically manipulated.

Abstract: An optical device comprising a 1×2 optical coupler on a planar substrate and a waveguide on the planar substrate, the waveguide having a first arm and a second arm coupled to the 1×2 optical coupler. The device also comprises an optical resonator on the planar substrate, wherein the optical resonator is optically coupled to the first arm and the optical resonator is substantially athermalized.

Abstract: An optical switch includes a microresonator comprising a plurality of silicon nanoparticles within a silicon-rich silicon oxide layer. The microresonator further includes an optical coupler optically coupled to the microresonator and configured to be optically coupled to a pump source and to a signal source. A method of optical switching includes providing an optical switch comprising an optical coupler and a microresonator having a plurality of nanoparticles and receiving an optical pulse by the optical switch, wherein at least a portion of the optical pulse is absorbed by the nanoparticles such that at least a portion of the microresonator undergoes an elevation of temperature and a corresponding refractive index change when the optical pulse has an optical power greater than a predetermined threshold level.

Abstract: Disclosed is a system including an integrated silicon-based structure including a microcavity configured to receive optical energy from an input beam carrying an optical signal and absorb the optical energy by a nonlinear multi-photon absorption process. For example, the multi-photon absorption process can be two-photon absorption (TPA). The integrated silicon-based structure further includes electrodes responsive to the nonlinear multi-photon absorption process in the microcavity for producing an electronic signal indicative of the optical signal. A related method is also disclosed.

Abstract: A system and method for controlling an optical filter is provided. The system and method includes dithering a delay of an optical path within an optical filter unit cell, measuring a position of a filter zero, measuring a position of a filter pole, or measuring positions of both a filter zero and a filter pole by observing an output of the unit cell when the delay is dithered, and using the measurement as feedback for maintaining the position of the filter zero at a desired position, maintaining the position of the filter pole at a desired position, or maintaining the positions of both the filter zero and the filter pole at desired positions.

Abstract: Disclosed are resonant optical modulators, and methods of use thereof, that achieve constant photon populations in the resonator by simultaneously modulating at least two variable modulation parameters.

Abstract: The invention relates to an optical modulator, comprising a first waveguide for a signal to be modulated, a second waveguide for a control signal, and an auxiliary waveguide, wherein the auxiliary waveguide is supported by a carrier which can be deflected to change a distance between the first waveguide and the auxiliary waveguide, wherein the carrier also comprises two layers with different coefficients of thermal expansion and the second waveguide is guided in such a way that a temperature of the carrier at least in a section can be manipulated by light transported by the second waveguide. The invention further relates to an integrated optical circuit comprising such an optical modulator, and to a modulation method which can be performed with such a modulator.

Abstract: An electromagnetically responsive element includes sets of arrangements of self-resonant bodies, such as atoms or quantum dots that form an effective dielectric constant, typically at or near a resonance.

Abstract: An electromagnetically responsive element includes sets of arrangements of self-resonant bodies, such as atoms or quantum dots that form an effective dielectric constant, typically at or near a resonance.

Abstract: A waveguide sensor capable of direct, real-time detection and monitoring of analytes in the vicinity of the waveguide surface without requiring the tagging or labeling of the analyte, is described. Analytic and numerical calculations have predicted that by locally detecting either changes in the evanescent field or changes in the light coupled out of the waveguide as a result of the presence of the analyte, high detection sensitivity will be able to be achieved.

Abstract: A first exemplary aspect of the present invention is a wavelength-tunable optical transmitter including: a semiconductor substrate (101); a wavelength-tunable light source that is formed on the semiconductor substrate (101) and includes at least a first reflector (102) of a wavelength-tunable type and a gain region (104); a semiconductor optical modulator formed on the semiconductor substrate (101); a first semiconductor optical waveguide (105c) that is formed on the semiconductor substrate (101) and smoothly connected to the wavelength-tunable light source; a second semiconductor optical waveguide (105d) that is formed on the semiconductor substrate and smoothly connected to the semiconductor optical modulator; a waveguide coupling region (108) in which the first and second semiconductor optical waveguides are collinearly coupled with a length LC that is not equal to m/2 (m: integer) times a complete coupling length LC0; and a second reflector (113) formed at an end of the waveguide coupling region (108).

Abstract: The waveguide-type polarizer includes: a Z-cut lithium niobate substrate; an optical waveguide having a ridge structure and formed on the substrate; a low refractive index film formed with a thickness satisfying 0?n·t/??0.3742 (where n is a refractive index, t (?m) is the thickness of the film, and ? (?m) is the wavelength of a light wave) on the side of the ridge structure; and a high refractive index film formed with a thickness satisfying 0.089?n·/? on the low refractive index film. The width of the ridge structure is a ridge width where the distribution of ordinary light of the light waves propagated through the optical waveguide changes and the distribution of extraordinary light of the light waves does not change, the angle of the ridge structure is less than 90°, and the waveguide-type polarizer has a function of transmitting extraordinary light.

Abstract: Fibre substrates act as a conduit for light along which response signals are transmitted to a controller in the form of an electronic device associated with a component. The processed signals are stored in a local memory to provide a component history and a prediction of future performance and life. Service and repair history may be added to the component device memory to enable a complete history to be stored with the component. A controller may transmit data to an external controller or display through typically a wireless connection. Power to the component electronics may be provided by an induction loop or transformer.

Abstract: A polarization beam splitter-polarization rotator-polarization beam combiner optical structure comprising a pair of polarization rotators having a polarization beam splitter associated with the input ends of the two polarization rotators, and a polarization beam combiner associated with output ends of the two polarization rotators, and a method of purifying a light signal comprising TE and TM modes by disassociating the primary TE and TM modes from first order splitter and rotation error components.

Abstract: Radiation detection systems and methods. In one approach, optical radiation can be detected by using the radiation to be detected as input to a high index contrast waveguide modulator that modulates a wavelength of light that falls within the detection band of a detector. In another approach, the optical radiation that is to be detected is combined with a high power CW boost mode signal in a waveguide, and the sum and/or difference frequencies are detected. In either approach, one can use grating couplers to couple the optical radiation of interest into a waveguide.

Abstract: An information processing apparatus in which its function can be improved by installing an additional module to an existing module in a module configuration system. A video information processing apparatus 100, which is an existing module, has the function of reading, from a network module 150 as an additional module, software held in the network module 150. The software held in the network module 150 includes control software for the network module and software for making the control software available to the existing video information processing apparatus 100. The software held in the network module 150 is added to the video information processing apparatus 100, and the network module 150 is operated by the video information processing apparatus 100.

Abstract: Disclosed is an optical element that includes: a light guide body into which light from a light-emitting element enters; carrier generation layer (6) formed in the light guide body, in which carriers are generated by the light from the light guide body; plasmon excitation layer (8) stacked on carrier generation layer (6), which has a plasma frequency higher than the frequency of light generated when carrier generation layer (6) is excited by the light from the light-emitting element; and wave vector conversion layer (10) stacked on plasmon excitation layer (8), which converts light incident from plasmon excitation layer (8) into light having a predetermined exit angle to output the light. Plasmon excitation layer (8) is sandwiched between low dielectric constant layer (7) and high dielectric constant layer (9).

Abstract: A method fabricates an optical switch comprising a microsphere coated with silicon nanocrystals. The method includes providing a silica optical fiber. The method further includes melting at least a portion of the fiber to form at least one silica microsphere. The method further includes coating the microsphere with a silica layer. The method further includes precipitating silicon nanocrystals within the silica layer by annealing the microsphere. The method further includes passivating the nanocrystals by annealing the microsphere in a hydrogen-containing atmosphere.

Abstract: A method of implementing optical deflection switching includes directing a tuning operation at a specific region of coupled optical resonators coupled to an input port, a first output port and a second output port, the coupled optical resonator including a plurality of cascaded unit cells; wherein the tuning operation interrupts a resonant coupling between one or more of the unit cells of the coupled resonators so as to cause an input optical signal from the input port to be directed from the first output port to the second output port.

Abstract: A novel electroabsorption modulator based on tuning the Fermi level relative to mid-gap states in a semiconductor. The modulator includes a semiconductor waveguide that has an input port and an output port. Between the input port and the output port is a section of the waveguide that functions as an electroabsorptive region. Adjacent to the electroabsorptive region are electrical contacts. In operation by adjusting voltages on the electrical contacts, the quasi-Fermi level in the electroabsorptive region of the semiconductor waveguide is brought above or below mid band-gap electronic states. As these states transition between occupancy and vacancy, the absorption coefficient for optical radiation in the electroabsorptive region of the semiconductor changes.

Abstract: Techniques are generally disclosed for optical devices that may be used to implement a variety of logic devices or other circuits by optical means. Example optical devices use a photodiode to alter the charge carrier concentration in a waveguide, thereby altering the index of refraction of the waveguide. The photodiode may be driven by an optical signal, which may be coupled to the photodiode through an optical waveguide. The optical signal may be configured to control the phase of coherent light coupled through the waveguide. A variety of logic devices and other circuits may be implemented by allowing the light coupled through the waveguide to constructively or destructively interfere with other coherent light.

Abstract: In a multilevel light intensity modulator of the invention, input light is branched into n (n is an integer of 2 or more), and respectively sent to n branching waveguides. On the branching waveguides are respectively provided MZI light modulating sections. The MZI light modulating sections branch the input light into two at a branching ratio different from 0.5:0.5, and respectively output a binary optical signal with a quenching ratio being deteriorated, by on/off driving with a binary electric signal. Then by coupling the light output from the MZI light modulating sections, an optical signal with the light intensity modulated to a 2n value not including the zero level is output. As a result quaternary or higher level light intensity modulation which does not include the zero level, can be realized by a practical configuration using a binary electric signal.

Abstract: The invention relates to a method for establishing a light beam (CLB) with substantially constant luminous intensity comprising the steps of establishing a light beam (LB) by means of a light source (SAL) and controlling an attenuation of said light beam (LB) on the basis of occurrences of luminous intensity peaks (IP) in said light beam (LB).