The present invention relates to a coherent detection array and methods of multiplexing for signal readout of the coherent detection array. The coherent detection array may be implemented on a photonic integrated circuit (PIC). It may comprise a plurality of coherent detection units coupling with connecting waveguides and electrical conducting paths, wherein the electrical conducting paths may manifest as readout channels for multiplexing electrical signals. The detection units may be configured to include free-space-to-waveguide couplers, optical couplers, and photodetectors. The coherent detection array enables multiplexing methods that may leverage extra degrees of freedom of the coherent detection array. These methods may include those enabled by the local oscillator and those related to the properties and responses of the components of the PIC-based detection array.

A light detection and ranging (LiDAR) apparatus capable of extracting speed information and distance information of objects in front thereof is provided. The LiDAR apparatus includes: a continuous wave light source configured to generate continuous wave light; a beam steering device configured to emit the continuous wave light to an object for a first time and stop emitting the continuous wave light to the object for a second time; a receiver configured to receive the continuous wave light that is reflected from the object to form a reception signal; and a signal processor configured to obtain distance information and speed information about the object based on the reception signal.

Disclosed herein are systems and methods for linearizing frequency chirp in a frequency-modulated continuous wave (FMCW) coherent LiDAR system. Exemplary methods can include generating a continuous wave laser signal having a frequency characteristic, in which the frequency characteristic can include a frequency chirp over a frequency band in at least one period; and receiving a signal based on the generated laser signal. The methods can further include mixing the received signal with a local oscillator signal, the local oscillator signal having the frequency characteristic; determining at least one beat frequency based on the mixed signal; sampling the mixed signal at a rate equal to at least two times the beat frequency; determining a correction signal based on the sampled signal; and applying the correction signal to the laser signal.

Aspects for an on-chip or integrated continuous-wave Light Detection and Ranging (LiDAR) are described herein. The aspects may include one or more laser light sources configured to generate one or more light beams and multiple light engines configured to respectively receive the light beams. The light frequency is modulated in a predefined pattern. A light transmitter of each light engine may be configured to receive a first portion of one of the light beams and transmit the first portion of the light beam at a predetermined angle. A light receiver of each light engine may be configured to receive the first portion of the light beam reflected from an object and transmit the reflected first portion of the light beam to a balanced detector. The balanced detector may be configured to detect a beat between the reflected first portion of the light beam with a second portion of the light beam.

A LIDAR measuring device and a method for determining the speed of particles in a measuring volume includes a narrowband continuous wave laser light source (1), which emits light which is coupled into a measuring branch (3) and a reference branch (4). The light coupled into the measuring branch (3) is at least partially emitted by a transmitting device in the direction of the measuring volume such that the emitted light is at least partially scattered and/or reflected by the particles in the measuring volume. A part of the scattered and/or reflected light is then received by a receiver device and is coherently superimposed with the light leaving the reference branch (4), and the resulting light beam is directed onto a detector (6) to generate a detector signal characteristic for the resulting light beam. Finally, the speed of the particles in the measuring volume is determined in an evaluation unit (11) by taking into account the detector signal.

Disclosed herein are systems and methods for linearizing frequency chirp in a frequency-modulated continuous wave (FMCW) coherent LiDAR system. Exemplary methods can include generating a continuous wave laser signal having a frequency characteristic, in which the frequency characteristic can include a frequency chirp over a frequency band in at least one period; and receiving a signal based on the generated laser signal. The methods can further include mixing the received signal with a local oscillator signal, the local oscillator signal having the frequency characteristic; determining at least one beat frequency based on the mixed signal; sampling the mixed signal at a rate equal to at least two times the beat frequency; determining a correction signal based on the sampled signal; and applying the correction signal to the laser signal.

Systems and methods for a silicon photonics integrated optical velocimeter are provided herein. In some embodiments, a method includes producing a laser output at a laser source; emitting the laser output from a plurality of emitters formed in an optical chip; receiving a plurality of reflected portions of the emitted laser output at an optical collector formed in the optical chip, wherein the plurality of reflected portions are reflected off of at least one surface; beating the laser output against the reflected portions of the emitted laser output, wherein one of the laser output or the reflected portions of the emitted laser output are modulated by at least one modulation frequency; and calculating a doppler shift for each of the plurality of reflected portions of the emitted laser output based on an output of the beating and the at least one modulation frequency.

A sensing system. In some embodiments, the system includes a first imaging radio frequency receiver, a second imaging radio frequency receiver, a first optical beam combiner, a first imaging optical receiver, a second optical beam combiner, and an optical detector array. The first optical beam combiner may be configured to combine optical signals of the imaging radio frequency receivers. The second optical beam combiner may be configured to combine the optical signals of the imaging radio frequency receivers, and the optical signal of the first imaging optical receiver.

Embodiments described herein are generally directed to a device that monitors for the presence of objects passing through or impinging on a virtual shell near the device, referred to herein as a “light curtain”, which is created by rapidly rotating a line sensor and a line laser in synchrony. The boundaries of the light curtain are defined by a sweeping line defined by the intersection of the sensing and illumination planes.

The invention relates to a FMCW lidar imager system with improved distance resolution. The imager system 1 comprises a reflector 42 configured to reflect, in the direction of the scene 2, a portion S.sub.or,nc of the backscattered object signal S.sub.or, which portion has not been collected by the collecting optical element 41. Thus, the collected portion S.sub.or,c of the backscattered object signal S.sub.or is formed from first light beams S.sub.or,c(1) that have not been reflected by the reflector 42 and from light beams S.sub.or,c(2) that have been reflected by the reflector 42. The heterodyne signal S.sub.h therefore has a principal component S.sub.h(1) associated with the light beams S.sub.or,c(1), and a secondary component S.sub.h(2) associated with the light beams S.sub.or,c(2). The processing unit 60 is configured to determine the distance z.sub.sc of the scene 2 on the basis of a beat frequency f.sub.b(2) of the secondary component S.sub.h(2) of the heterodyne signal S.sub.h.