In one embodiment, a lidar system includes a light source configured to emit local-oscillator light and pulses of light, where each emitted pulse of light is (i) coherent with a corresponding portion of the local-oscillator light and (ii) includes a spectral signature of one or more different spectral signatures. The lidar system also includes a receiver configured to detect the local-oscillator light and a received pulse of light, the received pulse of light including light from one of the emitted pulses of light scattered by a target located a distance from the lidar system, the one of the emitted pulses of light including a particular spectral signature of the one or more spectral signatures. The local-oscillator light and the received pulse of light are coherently mixed together at the receiver. The receiver includes one or more detectors and a frequency-detection circuit.

A device for scanning range measurement to an object has a light source that generates an optical output signal having a varying frequency. A plurality of optical processing units are connected optically in parallel to the light source. Each processing unit has an optical distribution matrix with a plurality of optical switches that distribute the optical output signals from the light source selectively to different optical waveguides. A plurality of free space couplers outcouple the optical output signals into the free space, and couple optical output signals, which were reflected on the object, into the associated optical waveguides as optical measurement signals. A polarization sensitive light splitter directs the optical measurement signals detectors that detect a superposition of the optical measurement signals with the optical output signals supplied via a local oscillator light path.

A LIDAR system includes a light source configured to output a source signal. The LIDAR chip is also configured to output a LIDAR output signal that exits from the LIDAR chip. The LIDAR system also includes an isolator adapter that includes an optical isolator configured to receive an adapter signal. The adapter signal includes light that is from the source signal and that has exited from the LIDAR chip before being received by the optical isolator. The isolator is configured to output light from the adapter signal in an isolator output signal. Additionally, the LIDAR output signal includes light from the isolator output signal.

The invention relates to a reduced-size FMCW lidar imager system. The imager system comprises an optical source 10 for a coherent, continuous and frequency-modulated primary signal S.sub.p in order to illuminate the scene 2; an optical collection element 41 configured to collect a backscattered signal S.sub.ret,c; a photodetector 50 intended to receive a heterodyne signal S.sub.h associated with the collected signal S.sub.ret,c; and a processing unit 60 configured to determine the distance z.sub.sc from the scene based on a beat frequency of the heterodyne signal s.sub.h. It is configured to fully direct the primary signal S.sub.p to the scene 2. It additionally comprises a reflector 42 configured to reflect a portion S.sub.pr,nc, called uncollected signal S.sub.ret,nc, of the backscattered signal S.sub.ret, not collected by the optical collection element 41, in the direction of the scene 2.

A LIDAR system outputs a system output signal such that the system output signal can be reflected by an object located outside of the LIDAR system. The system also receives a system return signal that includes light from the reflected LIDAR output signal. The system return signal and the system output signal each carries a first channel. The LIDAR system combine light that is from the system return signal and that carries the first channel with a reference signal so as to produce a composite signal beating at a beat frequency. Electronics operate the LIDAR system such that the first channel has a series of chirp cycles. Each chirp cycle includes a linear chirp section where a frequency chirp of the channel is linear. Multiple different sample periods fall within each of the linear chirp sections. The electronics calculate LIDAR data for each of the sample periods from the beat frequency of the composite signal during the sample period. The LIDAR data for a sample period indicates the radial velocity and/or distance between the LIDAR system and the object.

A time-of-flight (ToF) imaging system includes a photonic mixer device configured to perform ToF measurements using at least one photo-sensitive element. Each photo-sensitive element includes at least a first element with a modifiable first charge level, a second element with a modifiable second charge level, and a gate for transferring charges to a fixed potential. The ToF imaging system includes control circuitry configured to provide a control signal for the photonic mixer device. The control signal is configured to drive the at least one photo-sensitive element such that charge carriers generated in the at least one photo-sensitive element by received light are directed either to the first element, the second element or the gate, or such that charge carriers generated in the at least one photo-sensitive element by received light are directed either to the first element, the second element, the gate, or to the first and the second element.

An optical sensor system includes a set of epitaxial layers formed on a semiconductor substrate. The set of epitaxial layers defines a semiconductor laser having a first multiple quantum well (MQW) structure. Electromagnetic radiation is generated by the first MQW structure, emitted from the first MQW structure, and self-mixed with a portion of the emitted electromagnetic radiation that is returned to the first MQW structure. The set of epitaxial layers also defines a second MQW structure operable to generate a first photocurrent responsive to detecting a first emission of the semiconductor laser, and a third MQW structure operable to generate a second photocurrent responsive to detecting a second emission of the semiconductor laser. The optical sensor system also includes a circuit configured to generate a self-mixing interferometry (SMI) signal by combining the first photocurrent and the second photocurrent.

A method and system for simultaneously measuring multiple DOF GEs by a laser. The system comprises a measuring unit and a target mirror unit; the measuring unit comprises a laser emitting module, a polarizing beam splitter, a fixed reflector, a first λ/4 wave plate, a second λ/4 wave plate, a first polarizer, a first photodetector, an interference length measuring module and a 2D angle measuring module. The target mirror unit comprises a beam splitter and a reflector. The laser emitting module generates an emitting light L1. The polarizing beam splitter is used for (1) beam splitting, (2) beam combining, and (3) beam separating. The fixed reflector is used for reflecting backward the reference light L12 propagating only inside the measuring unit to return the reference light L12 to the polarizing beam splitter. The present invention can realize a simultaneous and rapid measurement of 5/6DOF GEs of a space object moving linearly along a linear axis; and a relative drift of position and attitude of two objects with 5/6DOF in a space can be longtime monitored.

A system for simultaneously measuring 3DOF LGEs by a laser and a method therefor, including a measuring unit and a target mirror unit, the measuring unit includes a laser emitting module, a polarizing beam splitter, a fixed reflector, a first photodetector, and an interference length measuring module; the target mirror unit includes a reflector; the laser emitting module generates an emitting light L1, the polarizing beam splitter is used for 1) “beam splitting” comprising splitting the emitting light L1 into a measuring light L11 and a reference light L12, the measuring light L11 is incident on the target mirror unit and is reflected back by the target mirror unit, so as to return to the measuring unit with a 3DOF LGEs signal; and 2) “beam combining” making the measuring light L11 and the reference light L12 superposed with each other at a spatial position, so as to form a combined beam L3; by measuring a position, frequency and phase drifts of the light L3, the 3DOF LGEs of a space object moving linearly along linear axes can be rapidly measured simultaneously; or a longtime monitoring 3DOF linear position drifts of two objects in space can be realized.

A LIDAR system which reduces or suppress the frequency shift induced by the movement of objects in a scene relative to the LIDAR, and which comprises a light source, an input aperture (101), a splitter (2) configured to split a reflected light into a reference channel (4) and a first imaging channel (3), a first imaging optical IQ receiver (5) configured to obtain a first interference signal, a reference optical IQ receiver (6) configured to obtain a reference interference signal, an imaging oscillator (111), configured to be temporarily coherent with the reflected light, at least a mixer (12), connected to the first imaging optical IQ (5) and to the reference optical IQ (6) and configured to obtain a first intermodulation product with a higher frequency and an intermodulation product of interest with its Doppler Shift scaled.