Abstract: The present disclosure provides methods and systems for flight velocimetry employing at least one bleaching laser, at least one detection laser, at least one dichroic mirror, an objective, a detection system, and a nano stage to bleach a dye to form a bleached blot in a flow pathway.

Abstract: A gas laser amplifier includes a housing, discharge electrode pairs, and an optical resonator. The housing includes an entrance window that allows entry of a first laser beam from outside and an exit window that allows exit of the first laser beam amplified. Each of the discharge electrode pairs excites a laser gas supplied between discharge electrodes facing each other in the housing. The optical resonator causes a second laser beam to oscillate with a gain of the excited laser gas in a non-incident state where the first laser beam from outside the housing does not enter the housing through the entrance window. In an incident state where the first laser beam enters the housing through the entrance window, the optical resonator suspends the oscillation of the second laser beam.

Abstract: To suppress the deterioration of signal quality in an optical signal, a LiDAR device comprises: a signal output means 20 for outputting a first electric signal in a first period, reducing the amplitude of the first electric signal outside the first period, and then outputting a second electric signal; a modulator 30 which outputs an optical signal modulated on the basis of the first electric signal or the second electric signal; and a control means 40 for applying, to the modulator 30, a bias voltage based on the optical signal modulated on the basis of the first electric signal.

Abstract: A sub-nanosecond laser system is disclosed. The sub-nanosecond laser system may include: a pump laser source operable to generate a pump laser beam having a pump wavelength; a first pump beam splitter operable to receive the pump laser beam and split the pump laser beam into at least a first split pump laser beam and a second split pump laser beam; a passively Q-switched seed laser operable to receive the first split pump laser beam and generate a seed laser beam; and an amplifier assembly operable to receive the second split pump laser beam and the seed laser beam. The amplifier assembly may include one or more amplifiers arranged in series in a multi-stage configuration, arranged in a multi-pass configuration, or a combination thereof.

Abstract: A light detection and ranging (lidar) sensor system may include a laser source configured to generate a beam, an electronic module, and one or more processors. The electronic module may generate, based on the beam, an optical signal that is frequency-shifted by a frequency offset relative to a local oscillator (LO) signal. The electronic module may control a transmitter to transmit the optical signal to an environment. In response to transmitting the optical signal, the electronic module may receive a returned optical signal that is reflected from an object in the environment. The electronic module may generate a digital signal based on the received signal. The electronic module may digitally mix the digital signal based on the frequency offset to generate a sample signal. The one or more processors may determine, based on the sample signal, a range to the object.

Abstract: An optical amplifier comprises a gain medium having an input surface and an output surface wherein the output surface is larger than the input surface. The gain medium may be frustum shaped. The optical amplifier includes a negative diverging lens to receive an extraction laser beam and to cause the laser beam to expand as the beam passes through the gain medium. The amplifier further comprises a positive collimating lens configured to receive the expanding amplified beam and reduce the divergence. The gain medium can be pumped by counter-propagating radiation. The fluence of the laser beam within the gain medium is configured to be near constant along the length of the gain medium and may be within 1.5-2.0 FSAT. The gain medium may be doped with dopant to provide gain, with larger concentration of dopants proximal the input surface and smaller concentration proximal the output surface.

Abstract: The FMCW LiDAR system includes an optical drive electronic circuit to receive a reference frequency signal and a beat frequency signal to generate a drive signal. The optical drive electronic circuit includes a TDC to calculate a phase difference between the reference frequency signal and the beat frequency signal and a digital ramp control to: provided the phase difference is a positive value, produce a ramp down control signal to increase a current chirp rate to an increased chirp rate; provided the phase difference is a negative value, produce a ramp up control signal to decrease the current chirp rate to a decreased chirp rate. The optical drive electronic circuit includes a digital integrator to generate a digital output based on at least one of the ramp down control signal or the ramp up control signal and a DAC to convert the digital output to an analog output.

Abstract: The light wave distance meter is disclosed, including: a distance measuring light-emitting unit; a light-receiving signal generating unit; and a control arithmetic unit. A light-receiving signal includes a first intermittent light-receiving signal corresponding to a first distance measuring light, a second intermittent light-receiving signal corresponding to a second distance measuring light, a third intermittent light-receiving signal corresponding to a third distance measuring light, and a fourth intermittent light-receiving signal corresponding to a fourth distance measuring light. The control arithmetic unit executes an error determination control to acquire a shift signal generated by shifting at least a phase of any one of the first to fourth intermittent light-receiving signals by 2?·n??/2 or 2?·n+?/2, and compares the phase of the shift signal and the phase of the intermittent light-receiving signal at least between either the first frequencies or between the second frequencies.

Abstract: The invention relates to a method of tracking a target on an orbital trajectory by a spacecraft, the method comprising an acquisition phase which comprises the steps of activating a lidar, acquiring signals from the lidar system, determining target trajectory data from the lidar signals, wherein the spacecraft is engaged on a trajectory to approach or inspect the target, which trajectory is determined based on the target trajectory data, and if the target is no longer detected, activating a short-range detection phase, comprising activation of a wide-field radar.

Abstract: A virtual image display system includes: a light source for projecting an image; a first beamsplitter including a first free-form curved surface; and a second beamsplitter including a second free-form curved surface facing the first free-form surface of the first beamsplitter, in which the first free-form curved surface is separated from the second-free form curved surface of the second beamsplitter by free space, and in which the first beamsplitter and the second beamsplitter are arranged to redirect light emitted from the light source toward a user to form a virtual image.

Abstract: In some general aspects, a light beam control apparatus includes: a spectral feature actuator associated with a set of different states, each state configured to cause an optical apparatus to generate one or more pulses of a light beam at a discrete value of a spectral feature of the light beam; and a controller in communication with the spectral feature actuator. The controller includes: an actuator drive module configured to cause the spectral feature actuator to transition among the set of different states according to a control waveform; a waveform module configured to compute the control waveform for the spectral feature actuator that governs the transition among the set of discrete values; and a predictive module configured to receive one or more sensed aspects of the spectral feature actuator and instruct the waveform module to adjust the control waveform based on the received sensed aspects.

Abstract: Techniques for identifying false-positive sensor observations include using sensor observations from different sensor modalities. The techniques may include receiving first sensor data (e.g., radar data) and second sensor data (e.g., lidar data) generated by different types of sensors of a vehicle that is operating in an environment. The techniques may also include determining an absence of an observation in the first sensor data at a location in the environment where an observation is indicated in the second sensor data. The techniques may also include receiving an indication that a retroreflective surface is present in the environment. Based at least in part on at least one of the retroreflective surface being present in the environment or the absence of a radar observation at the location in the environment where a lidar observation is indicated, the techniques may include determining that the observation in the second sensor data is a false-positive observation.

Abstract: An object of the present disclosure is to allow gain compensation with a simple configuration without adding a new device to the outside. The present disclosure discloses a rare earth doped fiber including a core doped with a rare earth and a cladding region around the core, wherein one or more cavities are provided inside the core, and at least one of the cavities are provided along a longitudinal direction of the rare earth doped fiber.

Abstract: A frequency modulated, continuous wave (FMCW) laser using a microchip gain medium, an optical coupling element, and a tuning element is described. The laser may be part of a coherent laser ranging system.

Abstract: A light detection and ranging (LIDAR) system for a vehicle, includes a first scanner that receives a beam transmitted along an optical axis and projects the beam, a second scanner that is positioned along the optical axis, one or more motors that are coupled to the first scanner and the second scanner, and one or more processors. The one or more processors are configured to generate, based on one or more components of a particular waveform, a signal indicating data including a relative phase between the first scanner and the second scanner, and transmit the generated signal to the one or more motors, the signal causing the one or more motors to rotate the first scanner and the second scanner.

Abstract: This application discloses a laser detection apparatus, a method for manufacturing the laser detection apparatus, and a terminal, and belongs to the field of laser detection technologies, for example, light detection and ranging (Lidar). The apparatus includes a multiphase signal generation circuit, an amplifier array, and a laser transmitter array. The amplifier array includes a plurality of first amplifiers, and the laser transmitter array includes a plurality of laser transmitters. A plurality of output ends of the multiphase signal generation circuit are connected to input ends of corresponding first amplifiers, and output ends of the plurality of first amplifiers are connected to corresponding laser transmitters.

Abstract: Provided is a light detection and ranging (LiDAR)-based inspection device including an ultrafast pulse source configured to generate a first ultrafast pulse and a second ultrafast pulse each having a pulse width ranging from 1 fs to 100 fs, a stage configured to generate a gating signal by adjusting a distance of flight of the first ultrafast pulse, a dispersing device configured to generate a chirp signal, based on the second ultrafast pulse reflected from a specimen, the chirp signal including a plurality of pulses having different wavelengths, a nonlinear optical generator configured to generate a nonlinear optical signal based on the chirp signal and the gating signal, and a detector configured to detect the nonlinear optical signal, wherein the gating signal temporally overlaps with some of the plurality of pulses included in the chirp signal in the nonlinear optical generator.

Abstract: In some implementations, an optical amplifier system includes a variable gain optical amplifier that is an erbium doped fiber amplifier. The variable gain optical amplifier may provide a first gain stage for an optical signal. The optical amplifier system may include a fixed gain optical amplifier that is an erbium-ytterbium doped fiber amplifier. The fixed gain optical amplifier may provide a second gain stage for the optical signal following the first gain stage.

Abstract: A gain adjuster, a gain adjustment method, and an optical line terminal are provided, to separately adjust a gain of a to-be-adjusted optical signal. The gain adjuster includes a light spot conversion component and a gain medium that are sequentially coupled. The gain adjuster further includes a pump laser. The light spot conversion component is configured to adjust light spot sizes of at least some optical signals in received optical signals to output a first optical signal transmitted in space. The pump laser is configured to excite the gain medium. The gain medium is configured to adjust a gain of the first optical signal to output a second optical signal.

Abstract: A LIDAR system includes a static monolithic LIDAR transceiver, a collimating optic, and a first rotatable wedge prism. The static monolithic LIDAR transceiver is configured to transmit a laser beam and receive reflected laser light from a first target object. The collimating optic is configured to narrow the transmitted laser beam to produce a collimated laser beam. The first rotatable wedge prism is configured to steer the collimated laser beam in a direction of the first target object based on the first rotatable wedge prism being in a first position.