A coherent LIDAR imaging system includes a laser source; an optical splitter/recombiner designed to split the laser radiation into a reference beam and into an object beam and to superpose the reference beam on a reflected object beam reflected by the scene; and an optical imager creating an image of the scene on a detector. The detector includes an array of pixels designed for detecting the reflected object beam and the reference beam which together form a recombined beam having a beat frequency representative of a range of the illuminated scene. The optical splitter/recombiner is configured to form an intermediate image of the reference beam in an intermediate image plane perpendicular to the optical axis.

A coherent LIDAR imaging system includes a laser source; an optical splitter/recombiner designed to split the laser radiation into a reference beam and into an object beam and to superpose the reference beam on a reflected object beam reflected by the scene; and an optical imager creating an image of the scene on a detector. The detector includes an array of pixels designed for detecting the reflected object beam and the reference beam which together form a recombined beam having a beat frequency representative of a range of the illuminated scene. The optical splitter/recombiner is configured to form an intermediate image of the reference beam in an intermediate image plane perpendicular to the optical axis.

An optical measurement device includes at least a multi-frequency laser configured to simultaneously generate a frequency-fixed carrier and at least one frequency-modulated subcarrier, an optical branching element, a dual frequency beat signal generator, a difference signal generator, and an arithmetic processing unit. Either the carrier or the subcarrier within the output light of the multi-frequency laser is used as first measurement light and either the carrier or the subcarrier having a frequency different from that of the first measurement light is used as second measurement light. The dual frequency beat signal generator separates and outputs a first complex beat signal derived from the first measurement light and a second complex beat signal derived from the second measurement light. The difference signal generator outputs a difference signal between the first complex beat signal and the second complex beat signal.

The present disclosure relates to a collaborative phase-shift laser ranging device based on differential modulation and demodulation of coarse and precise measuring wavelength and a ranging method thereof. A collaboration terminal is disposed at a target to be measured of a phase-shift laser ranging system, which can improve the intensity of measurement light and then irradiate the same back to a measuring terminal, thereby resolving the problem of low ranging accuracy caused by the attenuation of light intensity during long-distance ranging. The collaboration terminal detects coarseness gauge signals and modulates a laser source by means of differential modulation; the collaboration terminal detects precision gauge signals by means of difference frequency demodulation, and then the intensity of measurement light is improved by mixing and restoring the precision gauge signals and modulating the collaboration-terminal laser source.

A frequency modulation continuous wave (FMCW)-based system configured to convert measurements of a linearly modulated wave from a time-domain into a frequency-domain to produce a non-linear frequency signal, where the non-linear frequency signal comprises a known linear component representing the desired linear modulation and an unknown non-linear component representing the non-linearity of the modulation. The FMCW-based system is further configured to determine coefficients of a basis function approximating a difference between the non-linear frequency signal and the linear frequency component in the frequency domain. The FMCW-based system is further configured to detect one or multiple spectrum peaks in the distorted beat signal with the distortion compensated according to the basis function with the determined coefficients to determine one or multiple distances to the one or multiple objects in the scene.

A vehicle, Lidar system and method of detecting an object is disclosed. The Lidar system includes a photonic chip, and a laser integrated into the photonic chip. The laser has a front facet located at a first aperture of the photonic chip to direct a transmitted light beam into free space. A reflected light beam that is a reflection of the transmitted light beam is received at the photonic chip and a parameter of the object is determined from a comparison of the transmitted light beam and the reflected light beam. A navigation system operates the vehicle with respect to the object based on a parameter of the object.

An optoelectronic sensor, including a transmitting unit for transmitting a plurality of optical signals in each case to a plurality of segments of an object, and a receiving unit that includes a first multichannel analog-digital converter device, including: an analog-digital converter unit; a plurality of signal processing channels, the signal processing channels of the plurality of signal processing channels in each case including: a detection antenna for receiving optical signals; and a modulator for generating an individual signal encoding. Signals of the plurality of signal processing channels, with individual signal encoding, are transmittable together to the analog-digital converter unit, are converted, and may be associated once again with the corresponding signal processing channels due to the individual signal encoding via algorithms.

A vehicle, Lidar system and method of detecting an object is disclosed. The Lidar system includes a photonic chip having a laser, an on-chip frequency shifter, a combiner and a first set of photodetectors. The laser generates a transmitted light beam and an associated local oscillator beam within the photonic chip. The on-chip frequency shifter shifts a frequency of the local oscillator beam. The combiner combines a reflected light beam with the frequency-shifted local oscillator beam, wherein the reflected light beam is a reflection of the transmitted light beam from the object to generate a first electronic signal at the first set of photodetectors. A processor obtains a first measurement of a parameter of the object from the first electronic signal. The vehicle includes a navigation system for navigating the vehicle with respect to the object using at least the first measurement of the parameter.

A method and apparatus is provided to calibrate a LiDAR using a reflect array calibration target having a spatially varying spectral reflectance profile. A frequency modulated continuous wave LiDAR emits a beam that spans a range of wavelengths, and, therefore, spatially varying spectral features in the reflectance profile can be used as indicia of where the LiDAR beam hits the calibration target. For example, the center has one absorption wavelength and the periphery has another, such that alignment is achieved by changing the alignment direction to maximize the spectral feature at the one absorption wavelength while minimizing the spectral feature at the other absorption wavelength. Alternatively, at least one spectral feature can have a center wavelength that changes as a function of space. Thus, the LiDAR is aligned by changing the beam direction to shift the center wavelength to a value corresponding to the target center.

Systems and methods described herein are directed to optical light sources, such as an external cavity laser (ECL) with an active phase shifter. The system may include control circuitry for controlling one or more parameters associated with the active phase shifter. The phase shifter may be a p-i-n phase shifter. The control circuitry may cause variation in a refractive index associated with the phase shifter, thereby varying a lasing frequency of the ECL. The ECL may be configured to operate as a light source for a light detection and ranging (LIDAR) system based on generating frequency modulated light signals. In some embodiments, the ECL may generate an output LIDAR signal with alternating segments of increasing and decreasing chirp frequencies. The ECL may exhibit increased stability and improved chirp linearities with less dependence on ambient temperature fluctuations.