Abstract: An optical system for receiving light scanned from different light origination locations in space can include a Liquid Crystal (LC) waveguide (LCW), including first and second LCW light ports. A beamsteering LC electrode can be included in or coupled to the LCW and can be configured to vary a receiving direction of light received at the second LCW light port in response to a varying electrical input signal applied to the LC electrode to scan receiving of light at the second LCW light port from different light origination locations in space. A photodetector can be optically coupled to the first LCW light port, such as to detect waveguided light from different light origination locations in space received in response to the varying electrical input signal applied to the first LC electrode. Ranger, bright-spot locking, laser detection, direct detect and coherent lidar, wavelength detection, and other techniques and use cases are possible.

Abstract: A photonic circuit with a hybrid III-V on silicon or silicon-germanium active section, that comprises an amplifying medium with a III-V heterostructure (1, QW, 2) and an optical wave guide. The wave guide comprises a coupling section (31) facing a central portion of the amplifying medium, a propagation section (34, 35) and a modal transition section (32, 33) arranged between the coupling section and the propagation section. In the modal transition section, the optical wave guide widens progressively from the propagation section towards the coupling section.

Abstract: The LiDAR system includes a coherent receiver disposed in a reference path. The coherent receiver includes a 90° optical hybrid to receive a portion of an optical beam along the reference path and a local oscillator (LO) signal to generate multiple output signals. The coherent receiver includes a first photodetector to receive a first and a second output signal to generate a first mixed signal, and a second photodetector to receive a third and a fourth output signal to generate a second mixed signal. The LiDAR system further includes a processor to combine the first mixed signal and the second mixed signal to generate a combined reference signal to suppress a negative image of a reference beat frequency signal to estimate a phase noise of the optical source to determine range and velocity information of the target.

Abstract: An optical device including a waveguide grating is disclosed. The optical device may be used as an optical cavity for a laser device, for instance, of an integrated laser device for light detection and ranging (Lidar) applications. In one aspect, the optical device includes a waveguide grating for guiding light, a heating layer provided beneath or above the waveguide grating, and two or more contacts for passing a current through the heating layer, to generate heat in the heating layer. The heating layer is thermally coupled to the waveguide grating and is optically decoupled from the waveguide grating.

Abstract: A wavelength tunable laser device includes a substrate including silicon, the substrate having a waveguide, a first semiconductor element bonded to the substrate, the first semiconductor element including an active layer of a group III-V compound semiconductor, and a second semiconductor element bonded to the substrate, the second semiconductor element facing to the first semiconductor element in a direction along which light emitted from the first semiconductor element propagates, the second semiconductor element including a grating formed of a group III-V compound semiconductor. The grating selects a wavelength of light.

Abstract: Disclosed embodiments include laser systems. An illustrative laser system includes a tunable laser. A beam splitter is operatively couplable to an output of the laser and is configured to split light output from the laser into a first path and a second path. A first modulator is disposed in the first path and is configured to generate first set of sidebands. A bandpass filter circuit includes a fiber Bragg grating filter and is operatively couplable to receive output from the first modulator and to pass a selected sideband of the first set of sidebands. A lock circuit is disposed in the second path, is configured to determine and stabilize wavelength of the laser, and is further configured to cooperate with the fiber Bragg grating filter to maintain a static lock point for the laser while allowing output of the first path to be tunable with respect to the lock point.

Abstract: The present invention provides devices, systems, and methods for producing bi-photons without the need for complex alignment or source design by the user. The invention provides a tunable source of high-brightness, high-visibility, bi-photons that can be configured for a number of applications.

Abstract: An optical apparatus comprising at least two optoelectronic devices fabricated on the same substrate and in thermal communication with each other. A first optoelectronic device is configured to generate optical signals and provide them to an optical system via an optical output port. A second optoelectronic device is configured to provide heat compensation for the first optoelectronic device. An electrical circuitry provides first electrical signals to the first optoelectronic device and second electrical signals to the second optoelectronic device. The electrical circuitry is configured to adjust at least the second electrical signals to controllably adjust a temperature of the first optoelectronic device.

Abstract: A method for enhancement of spontaneous Raman scattering (SRS) from gases comprising a multimode blue laser diode which receives feedback from a near concentric bidirectional multipass cavity in such a way as to generate a circulating power of order 100 W for a sample volume of 10 mm3. The feedback, provided via a volume Bragg grating, reduces the laser bandwidth to 4 cm?1. Spectra of spontaneous Raman scattering from ambient atmospheric air, detected collinearly with the pump, were recorded with a limit of detection below 1 part-per-million.

Abstract: A ridge type semiconductor optical device includes a first conductivity type semiconductor layer including at least a first stripe section; an active layer including at least an active stripe section on the first stripe section; a second conductivity type semiconductor layer including at least a second stripe section on the active stripe section; a ridge electrode on the second stripe section; an insulation film on an end face of each of the first stripe section, the active stripe section, and the second stripe section; and a film heater on the insulation film, the film heater overlapping with the end face of at least the first stripe section.

Abstract: Apparatus for deflection of a beam of light includes a case, which is configured to be positioned in a path of the beam, and a liquid, which is contained within the case. An array of plates is disposed across a surface of the liquid. The plates are configured to rotate on the surface about respective axes, which are mutually parallel and are spaced apart by a predefined pitch. An actuator is configured to drive a rotation of the plates about the respective axes so as deflect the beam that is incident on the plates.

Abstract: One illustrative device disclosed herein includes a lower waveguide structure and an upper body structure positioned above at least a portion of the lower waveguide structure. In this example, the device also includes a grating structure positioned in the upper body structure, wherein the grating structure comprises a plurality of grating elements that comprise a tunable material whose index of refraction may be changed by application of energy to the tunable material.

Abstract: A laser apparatus includes: a light source configured to generate laser light; and an optical negative feedback unit configured to narrow a spectral line of the laser light using optical negative feedback. A modulation signal is input to the light source to modulate a frequency of the laser light. A modulation amount in the frequency of the laser light is detected. A modulation sensitivity is calculated from (i) the modulation amount and (ii) an intensity of the modulation signal.

Abstract: A laser apparatus according to the present disclosure includes: a laser output unit configured to perform laser oscillation; and a control unit configured to acquire first laser performance data obtained when the laser output unit performs laser oscillation based on a first laser control parameter, and second laser performance data obtained when the laser output unit performs laser oscillation based on a second laser control parameter, while laser output from the laser output unit to an external device is stopped, and determine whether the second laser performance data has been improved as compared to the first laser performance data.

Abstract: Systems and methods for measuring temperature in an environment by creating a first beam having an energy of about 50 mJ/pulse, and a pulse duration of about 100 ps. A second beam is also created, having an energy of about 2.3 mJ/pulse, and a pulse duration of about 58 ps. The first beam and the second beam are directed into a probe region, thereby expressing an optical output. Properties of the optical output are measured at a sampling rate of at least about 100 kHz, and temperature measurements are derived from the measured properties of the optical output. Such systems and methods can be used to measure temperature in environments exhibiting highly turbulent and transient flow dynamics.

Abstract: A pulsed laser output section outputs a laser beam having a predetermined wavelength as first pulses. An optical path determining section receives the first pulses and determines one among a plurality of optical paths for each of the first pulses for output. A parallelizing section parallelizes a traveling direction of light beams traveling, respectively, through the plurality of optical paths. A wavelength changing section receives outputs from the parallelizing section and changes the outputs to have different wavelengths for output. A focusing section receives and focuses outputs from the wavelength changing section. An optical fiber receives an output from the focusing section at a core end face. A timing control section is arranged to time outputs from the optical path determining section to the output of the first pulses. The focusing section is arranged to focus the outputs from the wavelength changing section on the core end face.

Abstract: A laser soldering device includes a laser source, a lens group, a temperature sensor, and a feedback controller. The laser source emits a laser beam, which is power-adjustable, according to a control signal. The temperature sensor receives infrared rays radiated when the laser beam is irradiated to the soldering point to detect the temperature of the soldering point, and correspondingly outputs a sensing signal according to the detected temperature. When the detected temperature falls into a first temperature range based on a target temperature, the feedback controller executes a PID algorithm to calculate a predicted error value according to an error value between the detected temperature and the target temperature. The feedback controller controls the laser source according to the predicted error value, and adjusts the power of the laser beam accordingly, so that the detected temperature can be substantially equal to the target temperature.

Abstract: An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

Abstract: In a first embodiment, an external cavity tunable laser, comprising a silicon photonics circuit comprising one or more resonators having one or more p-i-n junctions; wherein a voltage is applied to one or more of the p-i-n junctions. In a second embodiment, a method of operating an external cavity tunable laser, comprising sweeping out free-carriers from a resonator of the tunable laser by applying a voltage to a p-i-n junction of a waveguide of the resonator.

Abstract: A pulsed third-harmonic laser system includes a pulsed laser, an extra-cavity nonlinear crystal, and an intracavity nonlinear crystal. The pulsed laser generates fundamental laser pulses and couples out a portion of each fundamental laser pulse out of the laser resonator to undergo second-harmonic-generation in the extra-cavity nonlinear crystal. Resulting second-harmonic laser pulses are directed back into the laser resonator and mixes with the fundamental laser pulses in the intracavity nonlinear crystal to generate third-harmonic laser pulses. The pulsed third-harmonic laser system thus maintains a non-zero output coupling efficiency regardless of the efficiency of the second-harmonic-generation stage, while the third-harmonic-generation stage benefits from the intracavity power of the fundamental laser pulses.

Abstract: A wavelength beam combining device includes: a light source unit comprising a plurality of laser light sources, each being configured to emit a laser beam with a predetermined wavelength width; a light condensing member configured to condense the laser beams emitted from the light source unit; a diffraction grating on which the laser beams condensed by the light condensing member are incident; a resonator mirror disposed in an optical path of a diffracted beam from the diffraction grating; and an output control unit configured to turn off, among the plurality of laser light sources, at least laser light sources located farthest from an optical axis of the light condensing member, to reduce an output of the wavelength beam combining device relative to an output of the wavelength beam combining device when all the plurality of laser light sources are turned on.

Abstract: An example optical system architecture includes a diode laser source having an optical fiber. The diode laser source is configured to generate an optical signal having a main mode and side longitudinal modes and to output the optical signal along an optical path. An optical filter is in the optical path. The optical filter is configured to receive at least part of the optical signal, to output the main mode along the optical path, and to suppress the side longitudinal modes at least in part. One or more optical amplifiers are in the optical path after the optical filter. The one or more optical amplifiers are configured to receive at least part of the main mode, to amplify the at least part of main mode, and to output an amplified version of the at least part of main mode along the optical path.

Abstract: In one aspect, the present teachings provide a system for performing cytometry that can be operated in three operational modes. In one operational mode, a fluorescence image of a sample is obtained by exciting one or more fluorophore(s) present in the sample by an excitation beam formed as a superposition of a top-hat-shaped beam with a plurality of beams that are radiofrequency shifted relative to one another. In another operational mode, a sample can be illuminated successively over a time interval by a laser beam at a plurality of excitation frequencies in a scanning fashion. In yet another operational mode, the system can be operated to illuminate a plurality of locations of a sample concurrently by a single excitation frequency, which can be generated, e.g., by shifting the central frequency of a laser beam by a radiofrequency. The detected fluorescence radiation can be used to analyze the fluorescence content of the sample, e.g., a cell/particle.

Abstract: A nonlinear crystal comprising a first end face and an opposing second end face is described. The first and second end faces are separated along an optical axis of the nonlinear crystal by a length in the range of 0.25 mm and 2 mm. Although the length of the nonlinear crystal results in a reduction in the nonlinear effects induced on an optical field propagating through the crystal it also provides for reduced deviation experienced by the generated optical field when the nonlinear crystal is rotated. Therefore, when the nonlinear crystals are incorporated within an enhancement cavity their reduced length allows for the deviation of the output field to be minimised by servo control electronics arranged to adjust a single cavity mirror. This significantly reduces the complexity, and thus expensive of the servo control electronics when compared to those employed with the prior art enhancement cavities.

Abstract: A method for assessing spectroscopic sensor accuracy, includes building an a priori simulation of generalized etalon drift. A spectroscopic sensor is tested to determine use parameters. A specific drift model is generated by applying the determined use parameters to the built a priori simulation of generalized etalon drift. The specific drift model is analyzed to determine whether the spectroscopic sensor is satisfactory.

Abstract: The present description relates to a stabilized interferometric system comprising: a light source (210) for emitting an initial beam of coherent light; a spatial light modulator (220) configured to receive at least a first part of said initial beam and input data (203) and configured to emit a spatially modulated beam resulting from a spatial modulation of a parameter of said first part of said initial beam based on said input data; a scattering medium (230) configured to receive said spatially modulated beam; a detection unit (240) configured to acquire an interference pattern (IN0) resulting from the interferences between randomly scattered optical paths taken by the spatially modulated beam through the scattering material; a control unit (250) configured to vary the frequency of the laser source in order to at least partially compensate a change in said interference pattern resulting from a change in at least one environmental parameter.

Abstract: A light source device includes: a plurality of light sources that generate rays of light with different wavelengths corresponding to a plurality of target wavelengths located on a designated wavelength grid; a plurality of photodetectors that detect output powers of the plurality of light sources; a plurality of optical bandpass filters that are provided between the plurality of light sources and the plurality of photodetectors; a temperature adjustment unit that adjusts a temperature of an area around the plurality of light sources; and a processor that controls the temperature adjustment unit based on output signals of the plurality of photodetectors. Widths of passbands of the optical bandpass filters are less than a wavelength spacing in the wavelength grid.

Abstract: A device according to one example of principles described herein may include a backplane, electrochemical actuator, and an optical resonator, wherein the electrochemical actuator is located between the backplane and optical resonator. Applied energy may be used to modify the volume of the electrochemical actuator material modifying the resonant/interferometric absorption, transmission, and reflection at visible and/or infrared frequencies.

Abstract: A spatial light modulator and a beam steering apparatus including the same are provided. The spatial light modulator may include a distributed Bragg reflector provided on a substrate, a cavity provided on the distributed Bragg reflector, a grating reflector provided on the cavity, and a heater provided on the grating reflector.

Abstract: A control system for controlling a laser, comprising a sensor for sensing a physical value indicative of a characteristic of a laser beam emitted by the laser, a switch, a first controller and a second controller. Each controller is configured, to receive a further sensor value from the sensor, adjust a received setpoint value based on the received further sensor value to give an output value and cause the laser to operate in accordance with the output value. The switch is configured to switch between the controllers such that output values are provided from each controller in a cyclic fashion.

Abstract: An optical system can lock a wavelength of a tunable laser to a specified wavelength of a temperature-insensitive spectral profile of a spectral filter. In some examples, the spectral filter, such as a Fabry-Perot filter, can have a temperature-insensitive peak wavelength and increasing attenuation at wavelengths away from the peak wavelength. The spectral filter can spectrally filter the laser light to form filtered laser light. A detector can detect at least a fraction of the filtered laser light. Circuitry coupled to the detector and the laser can tune the tunable laser to set a signal from the detector to a specified value corresponding to a specified wavelength in the spectral profile, and thereby adjust the selectable wavelength of the tunable laser to match the specified wavelength. In some examples, the optical system can include a polarization rotator, and can use polarization to separate incident light from return light.

Abstract: An imaging system for capturing an object includes a plurality of light sources for illuminating the object and a plurality of optical sensors. The plurality of light sources emit light radiation and the plurality of optical sensors are arranged to detect light radiation reflected from the object.

Abstract: A display apparatus includes a substrate in which a plurality of pads are disposed, a plurality of micro LEDs, wherein each micro LED from among the plurality of micro LEDs is electrically connected to a respective group of pads from among the plurality of pads and mounted on the substrate, and a plurality of protrusion members, wherein each protrusion member from among the plurality of protrusion members protrudes from the substrate and is formed adjacent to a respective pad from among the plurality of pads.

Abstract: A method for fabricating an optical element is provided. The fabrication method includes the following steps. A substrate is provided. A plurality of first dielectric layers, a plurality of metal layers of Ag or its alloy and a plurality of second dielectric layers are formed over the substrate. The plurality of first dielectric layers and the plurality of metal layers are alternately formed over the substrate. The plurality of second dielectric layers are formed on one side away from the substrate of the plurality of metal layers and located between the plurality of metal layers and the plurality of first dielectric layers. An optical element fabricated by the method is also provided.

Abstract: The present disclosure is directed to an optical device including at least one temperature-dependent tunable element for controlling a wavelength of an optical signal, a first temperature control circuit for controlling a temperature of a first region of the optical device; and a second temperature control circuit for controlling a temperature of a second region of the optical device. The second region may include a portion of the first region. The second region may be smaller than the first region. The tunable element may be positioned in the second region such that a temperature of the tunable element is controlled based on the second temperature control circuit controlling the temperature of the second region. The tunable element may be one of (i) a laser for transmitting an outgoing optical signal and (ii) an optical filter coupled to a photodetector for receiving an incoming optical signal.

Abstract: A mode-locked solid state laser apparatus including an optical film, a gain medium crystal, a Fabry-Perot element, a first mirror, a second mirror, a third mirror and an output coupler is disclosed. The optical film is configured to receive a pumping light having a first wavelength incident in a first direction. The gain medium crystal receives the pumping light passing the optical film, and generates an initial laser beam having a second wavelength, wherein the initial laser beam forms a first optical path starting at one end thereof from the gain medium crystal. The Fabry-Perot element is disposed on the other end of the first optical path opposite to the one end, and reflects the initial laser beam along a second optical path having one end thereof starting from the Fabry-Perot element.

Abstract: A laser radar device includes: a wavelength-tunable light source; an optical branch coupler dividing light emitted by the wavelength-tunable light source into local and transmission light; an optical phase modulator applying, to the transmission or local light, frequency shifts for wavelength discrimination of different shift amounts corresponding to respective wavelengths of light emitted by the wavelength-tunable light source; a wavelength separator switching between light paths for output, in response to wavelength of transmission light; an optical antenna emitting into space transmission light output by the wavelength separator, and receiving, as received light, backward-scattered light generated from transmission light in space in which lines of sight corresponding to respective wavelengths of the transmission light are determined; an optical heterodyne receiver receiving local light and received light, and performing heterodyne detection; and a signal processor performing frequency analysis of the optic

Abstract: A system and method for colorimetric calibration is described herein. A system for performing color calibration is described, comprising at least one broad spectrum light emitting diode, at least one light diffuser plate, at least one interference filter, and a camera, the camera comprising at least one sensor for detection of colors, wherein a spectral response within 5% error of a ground truth method can be achieved. A method for performing color calibration is described, comprising transmitting light from at least one broad spectrum light emitting diode, scattering light with at least one light diffuser plate, filtering light with at least one interference filter, detecting light at a camera sensor, mapping an intensity value for each pixel of the camera sensor, and creating a quantum efficiency curve for each of red, green, and blue channels.

Abstract: Fine-structure in the transverse mode of an excimer laser beam is minimized by having a plurality of resonator mirrors located at each end of a linear excimer laser. At one end, a highly-reflective end mirror and a partially-reflective end mirror are inclined at small angle with respect to each other. At the other end, two output-coupling mirrors are inclined at a small angle with respect to each other. This arrangement of resonator mirrors generates a composite laser beam that blurs any fine structure.

Abstract: A pluggable bidirectional optical amplifier module may include preamp and booster optical amplifiers and a housing. The preamp optical amplifier may be configured to amplify optical signals traveling in a first direction. The booster optical amplifier may be configured to amplify optical signals traveling in a second direction. The housing may at least partially enclose the preamp optical amplifier and the booster optical amplifier. The pluggable bidirectional optical amplifier module may have a mechanical form factor that is compliant with a pluggable communication module form factor MSA. A colorless mux/demux cable assembly may be operated with the pluggable bidirectional optical amplifier. The colorless mux/demux cable assembly may include a 1:N optical splitter a N:1 optical combiner coupled side-by-side to the 1:N optical splitter, a first fiber optic cable optic cable, and a second fiber optic cable.

Abstract: Examples of the present disclosure include a tunable laser comprising a waveguide including gain section. The waveguide overlies and is optically coupled to another waveguide. The another waveguide has a reflector at one end. A laser cavity is formed in the waveguides.

Abstract: A photonic integrated circuit (PIC) spectrometer for sensing the spectroscopic signature of airborne molecules, comprising a dispersive element to separate the spectral information spatially, and a tuning mechanism for said dispersive element to convert the spectral information to time-dependent information. The approach allows the PIC spectrometer to have a single (or a few) output pin(s), enabling sensing of the environment with a simple packaged chip that is compact, lightweight, energy efficient and low cost, making it suitable for platforms that have a small form factor, a small power budget, and are cost sensitive, such as mobile devices.

Abstract: An image sensor is disclosed. The image sensor includes: a common node heavily doped with dopants of a first conductivity type, the common node being within the substrate and abutting the front surface of the substrate; and a sensing node heavily doped with dopants of a second conductivity type opposite to the first conductivity type, the sensing node being within the substrate and abutting the front surface of the substrate; an interconnect structure, wherein the front surface of the substrate faces the interconnect structure; a distributed Bragg reflector (DBR) between the front surface of the substrate and the interconnect structure; a first contact plug passing through the DBR and coupling the common node to the interconnect structure; and a second contact plug passing through the DBR and coupling the sensing node to the interconnect structure.

Abstract: A method and apparatus for characterizing an optical element. The optical element is part of a laser and is mounted on a translation stage to scan the optical element transverse to an intracavity laser beam. A performance characteristic of the laser is recorded as a function of position of the optical element.

Abstract: A modulated light source includes an FP laser that emits light in a plurality of Fabry-Perot (FP) modes, a band-pass filter whose center wavelength can be modulated, a light reflector that selectively feeds only light having passed through the modulation filter back to the FP laser, and a wavelength adjustment mechanism that adjusts the center wavelength so as to coincide with one of the predetermined FP mode when the light fed back to the FP laser is used as seed light for stimulated emission of radiation to cause selective light emission at an oscillation wavelength.

Abstract: In one embodiment, a lidar system includes a light source configured to emit an optical signal and a receiver that includes one or more detectors configured to detect a portion of the emitted optical signal scattered by a target located a distance from the lidar system. The lidar system also includes a photonic integrated circuit (PIC) that includes an input optical element configured to receive the portion of the scattered optical signal and couple the portion of the scattered optical signal into an input optical waveguide. The input optical waveguide is one of one or more optical waveguides of the PIC configured to convey the portion of the scattered optical signal to the one or more detectors of the receiver. The lidar system further includes a processor configured to determine the distance from the lidar system to the target.

Abstract: An electro-optical system has a laser drive electronic circuit, a laser light source and an optical interferometer, forming a closed loop. The laser drive electronic circuit is arranged to receive a reference frequency as input, and a beat frequency as feedback. The laser drive electronic circuit generates a drive output based on a phase difference between the reference frequency and the beat frequency. The optical interferometer, coupled to the laser light, generates optical energy at the beat frequency.

Abstract: Aspects described herein include an optical waveguide emitter that includes a first optical waveguide and a second optical waveguide that are evanescently coupled and collectively configured to selectively propagate only a first mode of a plurality of optical modes. Each of the first optical waveguide and the second optical waveguide extend through an input waveguide section, a turning waveguide section, and an output waveguide section. One or more of the input waveguide section, the turning waveguide section, and the output waveguide section includes an optically active region. The optical waveguide emitter further includes a refractive index-increasing feature in the turning waveguide section.

Abstract: A multi-section laser device is configured with a gain section and an integrated photodetector section. The photodetector section, rather than being a separate component, is integrated directly into the body of the laser. The integrated photodetector section absorbs photons generated by the gain section and creates a photocurrent that is proportional to the output of the multi-section laser device. The measured photocurrent is usable to calculate power output of the multi-section laser device and to identify any adjustments that may be needed to be made to the laser in order to achieve desired laser light output.

Abstract: Disclosed herein are multi-layered optically active regions for semiconductor light-emitting devices (LEDs) that incorporate intermediate carrier blocking layers, the intermediate carrier blocking layers having design parameters for compositions and doping levels selected to provide efficient control over the carrier injection distribution across the active regions to achieve desired device injection characteristics. Examples of embodiments discussed herein include, among others: a multiple-quantum-well variable-color LED operating in visible optical range with full coverage of RGB gamut, a multiple-quantum-well variable-color LED operating in visible optical range with an extended color gamut beyond standard RGB gamut, a multiple-quantum-well light-white emitting LED with variable color temperature, and a multiple-quantum-well LED with uniformly populated active layers.