Abstract: An amplifier arrangement for increasing power and energy includes a multipass cell and at least one gain medium, wherein the multipass cell has concavely curved mirrors and the gain medium is arranged within the multipass cell in such a way that the pump radiation passes through the gain medium multiple times and is absorbed by the gain medium and wherein a laser beam to be amplified passes through the gain medium, characterized in that the mirrors are designed and arranged such that a White multipass cell is formed and the pump radiation and the laser beam to be amplified have large cross-sections at the positions at which mirrors, gain media and other optical components are arranged.

Abstract: A method includes receiving lidar data associated with remote sensing of moving water, and calibrating the lidar data, the calibration being based on one or more measurements contemporaneously measured with remote sensing of the moving water. The method includes refining the calibrated lidar data, the refinement being based on bubble detection associated with the moving water, where the refining includes discriminating between one or more signals associated with the bubble detection and one or more signals associated with non-bubble background detection. The method includes determining, from the refined lidar data, a bubble mask via feature detection based on depolarization ratio, and determining, based on the bubble mask, one or more bubble characteristics associated with the moving water.

Abstract: An optical apparatus includes a first deflection unit configured to deflect illumination light from a light source unit to scan an object and deflect reflected light from the object, a first light guiding unit configured to guide the illumination light from the light source unit to the first deflection unit and guide the reflected light from the first deflection unit to a light receiving unit, and a second light guiding unit configured to guide the illumination light from the light source unit to the light receiving unit, wherein the first light guiding unit includes a first passing region and a reflective region, and wherein the second light guiding unit is configured to guide, to the light receiving unit, light reflected in the reflective region without going through the object among the illumination light from the first deflection unit.

Abstract: The subject matter of this disclosure relates to a system, a method, and an apparatus for power monitoring and blockage detection in a lidar device. An example method includes: emitting, by a transmitter of a lidar device, an optical signal toward a maintenance area that is inside the lidar device and outside a field of view for the lidar device; measuring, by a power monitoring circuit of the lidar device, an intensity of an incident signal corresponding to the optical signal; comparing the measured intensity with a target intensity value; and adjusting, based on the comparison, an electrical control signal provided to the transmitter.

Abstract: A LIDAR system for scene surveying comprises a spatial light modulator for displaying a diffractive pattern comprising a hologram of a light footprint, and a light source for illuminating the diffractive pattern to form a holographic reconstruction of the light footprint on a holographic replay plane in the scene. The light footprint comprises an array of light features. The system comprises a display driver for controlling the spatial light modulator and changing the diffractive pattern with time. The diffractive pattern is changed with time such that each light feature of the array of light features scans a respective sub-area of the scene. The system comprises a detection system having a plurality of light detecting elements and that is configured such that each light detecting element detects light from a respective individual field of view within the scene. Each sub-area of the scene contains a plurality of individual fields of view.

Abstract: An optical amplifying fiber includes: at least one single core portion doped with a rare-earth element; an inner cladding portion configured to enclose the at least one core portion, the inner cladding portion having a lower refractive index than maximum refractive index of each core portion; and an outer cladding portion configured to enclose the inner cladding portion, the outer cladding portion having a lower refractive index than refractive index of the inner cladding portion, wherein the inner cladding portion includes a plurality of air bubbles.

Abstract: A system for communicating supervisory information between amplifier nodes in an optical communication network utilizes modulation of an included pump source to superimpose the supervisory information on data signals (typically customer data signals) propagating between the amplifier nodes transmitted customer signals. The modulated pump appears as a modulated envelope on the amplified data signal exiting the amplifier node, and may be recovered by suitable demodulation components located at the second node (i.e., the destined receiver of the supervisory information). The supervisory information may include monitoring messages, provisioning data, protocol updates, etc., and is utilized as an input to an included modulator, which then forms a drive signal for the pump controller.

Abstract: An example electronic system utilizing an optical ranging, proximity, and/or image sensor configured with retroreflective mechanisms to reduce unwanted optical noise at an optical radiation receiver are provided. The example ranging, proximity, and/or image sensor is configured to include a housing cap having a transmission opening and a receiving opening. The example sensor may further include an optical radiation source positioned to direct ranging optical radiation through the transmission opening toward a target object. An optical radiation receiver is positioned to receive ranging optical radiation reflected off the target object through the receiving opening. A retroreflective mechanism implemented on a surface of the housing cap directs unwanted optical noise back towards an unwanted optical noise source and away from the optical radiation receiver. Properties of the target object may be determined based on one or more properties of the ranging optical radiation received at optical radiation receiver.

Abstract: The present invention relates to a lidar (1000) comprising an emitter (1100) and a receiver (1200), wherein the receiver (1200) comprises a discrete amplification photon detector (1210), wherein the receiver (1200) comprises a discriminator (1220), wherein the discriminator (1220) has an input connected to an output signal of the discrete amplification photon detector (1210), and wherein the discriminator (1220) is configured to output a signal indicating that the output signal of the discrete amplification photon detector (1210) is higher than a predetermined threshold.

Abstract: Systems and methods for analyzing laser beam characteristics in high-speed laser motion systems, wherein the characteristics include laser travel speed, velocity, and acceleration, wherein the high-speed laser motion systems comprise a laser for generating a laser beam, comprising determining a location of the first pin-hole sensor within the predetermined field of view; determining a location of the second pin-hole sensor within the predetermined field of view; defining a travel distance of the laser beam; measuring the amount of time to travel from the location of the first pin-hole sensor to the location of the second pin-hole sensor; and dividing the travel distance by the amount of time to travel from the location of the first pin-hole sensor to the location of the second pin-hole sensor to calculate the velocity of the laser beam between the first pin-hole sensor and the second pin-hole sensor.

Abstract: A system for checking the attitude angles of wheels is provided, in a manner that is known per se, with a vertical measuring or column 1 on which some transmitters and receivers of electromagnetic signals are installed—for example coherent light illuminators (typically lasers) and associated reflected light sensor—which overall define a group of distance sensors. According to the disclosure, the proposed system is produced using distance sensors appropriately fitted on a single vertical measuring structure which is positioned, on a side of a movement path, where the vehicle equipped with wheels moves, that has a substantially transverse direction with respect to the acquisition direction of the distance sensors.

Abstract: A laser radar device includes: a light source; a mirror rotatable about a rotation shaft to reflect laser light emitted by the light source; a window; and a detector to detect laser light. The mirror has a low reflection area having a lower reflectance than the other region of the mirror, in a state where a mirror surface faces toward the light source, at position adjacent to the light source than the detector in an axial direction of the rotation shaft and adjacent to the window than a region where the laser light emitted by the light source hits for a first time in a radial direction of the rotation shaft. The window has an inclined posture in which a distance from the rotation shaft is shorter at position adjacent to the detector than at position adjacent to the light source.

Abstract: A laser system for the generation of ultrashort optical pulses of light including an oscillator emitting low power and negatively chirped optical pulses with a spectral bandwidth W1, a dispersive connecting segment to maintain the sign of the chirp of the pulses of the oscillator, an optical amplifier for amplifying the optical light pulses and a negative group velocity dispersion segment for compensating phase contributions of the whole propagation process. During the propagation from the output of the oscillator to the end of the optical amplifier, the chirp of the light pulses will change once from negative to positive chirp. After a final compression stage ultrashort optical pulses can be generated.

Abstract: In some implementations, a device may generate a data set including at least modal gain values and modal loss values for a semiconductor optical amplifier (SOA) slice. The device may determine, based on the data set, respective widths for a plurality of slices of an SOA using an autoregressive model. A width, of the respective widths, for a slice, of the plurality of slices, may be associated with a maximum conversion efficiency achievable for the slice at a given current density. The device may generate information indicating a geometry for the SOA based on the respective widths for the plurality of slices.

Abstract: A planar waveguide amplifier includes a planar waveguide including a flat plate-like core; a first cladding provided on a first principal face of the core; and a second cladding provided on a second principal face of the core, and signal light and pumping light travel into the planar waveguide so that the signal light and the pumping light propagate inside the core in such a manner that optical paths of the signal light and the pumping light overlap each other, and in a zig-zag manner, and the core is an amplification medium containing a rare-earth element serving as an active ion of a three-level system, and absorbs the signal light on the basis of a reduction in intensity of the pumping light.

Abstract: A large-scale and high-precision absolute distance measurement system based on an all-fiber femtosecond laser, including: a first all-fiber femtosecond laser, a second all-fiber femtosecond laser, a fiber optic splitter, a first fiber optic circulator, a wavelength division multiplexer, an achromatic fiber collimator, a first fiber optic combiner, a second fiber optic combiner, a second fiber optic circulator, a semiconductor laser, a first photodetector, a second photodetector, and a data acquisition and processing module.

Abstract: A method for Time-of-Flight (ToF) sensing of a scene is provided. The method includes performing, by a ToF sensor, a plurality of first ToF measurements using a first modulation frequency to obtain first measurement values. A respective correlation function of each of the plurality of first ToF measurements is periodic and exhibits an increasing amplitude over distance within a measurement range of the ToF sensor. The method additionally includes determining a distance to an object in the scene based on the first measurement values.

Abstract: A pulsed optical beacon source is formed of a fiber-based amplifier including a preamplifer stage (responsive to a CW seed laser source) and a booster stage coupled to the output of the preamplifier stage. The pump input to at least one stage is pulsed and controlled in a manner that allows for the formation of a pulsed beacon output that is able to perform the PAT requirements of a beacon source, while also allowing for a low bit rate (e.g., a few Hz to a few kHz) upstream data signal to be sent between the beacon source and a target's optical receiver.

Abstract: The present disclosure is related to field of Fiber Feedback (FFB) technology, and provides a method and system for estimating the distance between a fiber end and a target. The method includes illuminating, by a Light Emitting, Transmitting and Detecting (LETD) system, the target with laser light of different wavelengths having low and high water absorption coefficients, using different laser light sources, as well as receiving a returned signal corresponding to the incident laser light of different wavelengths, and detecting the returned signal to measure intensity values of the returned signal of a specific wavelength. Using the measured intensity values, a processing unit may estimate distance between the fiber end and the target. The present disclosure enables accurate estimation of distance between a fiber end and the target. The present disclosure also provides a robust distance estimation technique which is compatible with different types of targets.

Abstract: A fiber support assembly includes: a first glass tube, wherein the first glass tube is attached to a microlens or lenslet of a microlens or lenslet array; a second glass tube at least partially disposed within the first glass tube; and a gain fiber disposed within the second glass tube, wherein the gain fiber has a first tapered end cap, and wherein the gain fiber with the first tapered end cap is aligned to the microlens or lenslet attached to the first glass tube. The fiber support assembly may further include: a pump fiber disposed within the second glass tube, wherein the pump fiber has a second tapered end cap; and a reflector configured to receive counter-pumping light from the pump fiber and direct the counter-pumping light to the first tapered end cap of the gain fiber.