A frequency-modulated continuous wave (FMCW) LIDAR can be configured to reduce re-reflection and cross-coupling in the FMCW LIDAR. A first laser can be configured to generate a ranging signal, and a second laser can be configured to generate a local oscillator signal. A feedback control can be configured to maintain an offset between the ranging signal and the local oscillator signal. The offset can be a non-zero value. A transmit portion configured to emit a reference laser signal based on the ranging signal into an environment. A receiver portion can be configured to receive a return laser signal from the environment. The return laser signal can be a reflected version of the reference laser signal. A receiver photodetector can be configured to combine the return laser signal and the local oscillator signal.

A light receiver array according to the present invention is constituted by array-aligning plural receivers having slow light waveguides of photonic crystals, and a LiDAR device according to the present invention is constituted by linearly arranging a light receiver array and a transmitter. An arranging relationship of plural receivers of the light receiver array is an array-like element formed by array-aligning plural receivers having the slow light waveguides of photonic crystals, and the array alignment is defined by alignment for defining a position relationship between the plural receivers constituting the light receiver array, and orientation for defining a direction of each receiver. A relationship p=λ/sin Δθr is satisfied between the alignment pitch p, wavelength λ of the reception light, and an arrival angle Δθr when a phase difference between reception lights received by waveguide ends of adjacent receivers is one wavelength. Such a constitution that the arrival angle Δθr is equal to a widening angle Δθt of radiation light is suitable.

A circuit, including: a photodetector including a first readout terminal and a second readout terminal different than the first readout terminal; a first readout circuit coupled with the first readout terminal and configured to output a first readout voltage; a second readout circuit coupled with the second readout terminal and configured to output a second readout voltage; and a common-mode analog-to-digital converter (ADC) including: a first input terminal coupled with a first voltage source; a second input terminal coupled with a common-mode generator, the common-mode generator configured to receive the first readout voltage and the second readout voltage, and to generate a common-mode voltage between the first and second readout voltages; and a first output terminal configured to output a first output signal corresponding to a magnitude of a current generated by the photodetector.

A window material for protecting near infrared light emitting lasers and or detectors is coated with a conductive coating that reduces the reflection at the wavelengths and angles of incidence of interest. The conductive coating allows the window to be heated by applying a bias across connected electrodes to remove or prevent the condensation of liquid water and the buildup of ice. The conductive material in the coating has some optical absorption in the hear infrared region of about 800 to 1600 nm, which in combination with multiple intervening dielectric layers also allows the transmission of 90% of the light while obtaining a resistance of less than about 30 Ohms-square. The coating reduces reflection loses from the window, without decreasing transmission by more that about 10%.

Various examples for multi-tone continuous wave detection and ranging are disclosed herein. In some embodiments, an initial signal is generated using initial radio frequency (RF) tones, and is emitted as a multi-tone continuous wave signal. The initial signal is reflected from a target and received as a reflected signal. Resultant RF tones, including a frequency and a power, are determined from the reflected signal in a frequency domain. A frequency-domain sinusoidal wave is fitted to the resultant RF tones in the frequency domain, and a distance to the target is determined using a modulation of the frequency-domain sinusoidal wave.

Provided are methods for unsupervised domain adaptation for LiDAR segmentation via enhanced pseudo-labelling techniques, which can include training a machine learning model to perform a segmentation task for a source domain using a first sample set. Some methods also include generating a second sample set by applying the trained model to one or more unannotated samples associated with a target domain, and annotating the one or more unannotated samples with one or more pseudo-labels corresponding to an output of the trained machine learning model. Some methods also include generating a third sample set that includes at least one sample formed by concatenating a first sample from the first sample set and a second sample from the second sample set with target inputs. Some methods also include updating the trained machine learning model to perform the segmentation task for the target domain. Systems and computer program products are also provided.

Provided are methods for unsupervised domain adaptation for LiDAR segmentation via enhanced pseudo-labelling techniques, which can include training a machine learning model to perform a segmentation task for a source domain using a first sample set. Some methods also include generating a second sample set by applying the trained model to one or more unannotated samples associated with a target domain, and annotating the one or more unannotated samples with one or more pseudo-labels corresponding to an output of the trained machine learning model. Some methods also include generating a third sample set that includes at least one sample formed by concatenating a first sample from the first sample set and a second sample from the second sample set with target inputs. Some methods also include updating the trained machine learning model to perform the segmentation task for the target domain. Systems and computer program products are also provided.

One example device comprises a plurality of emitters including at least a first emitter and a second emitter. The first emitter emits light that illuminates a first portion of a field-of-view (FOV) of the device. The second emitter emits light that illuminates a second portion of the FOV. The device also comprises a controller that obtains a scan of the FOV. The controller causes each emitter of the plurality of emitters to emit a respective light pulse during an emission time period associated with the scan. The controller causes the first emitter to emit a first-emitter light pulse at a first-emitter time offset from a start time of the emission time period. The controller causes the second emitter to emit a second-emitter light pulse at a second-emitter time offset from the start time of the emission time period.

One example device comprises a plurality of emitters including at least a first emitter and a second emitter. The first emitter emits light that illuminates a first portion of a field-of-view (FOV) of the device. The second emitter emits light that illuminates a second portion of the FOV. The device also comprises a controller that obtains a scan of the FOV. The controller causes each emitter of the plurality of emitters to emit a respective light pulse during an emission time period associated with the scan. The controller causes the first emitter to emit a first-emitter light pulse at a first-emitter time offset from a start time of the emission time period. The controller causes the second emitter to emit a second-emitter light pulse at a second-emitter time offset from the start time of the emission time period.

There are provided methods and systems for producing a wave-beam having substantially constant lateral extent over a desired range of distances, and interrogation and response system and methods utilizing the same. The method for producing a wave-beam having substantially constant lateral extent includes generating a plurality of at least partially incoherent constituent wave-beams having different divergences and directing the plurality constituent wave-beams to propagate along substantially parallel propagation axes such that the constituent wave-beams at least partially overlap and superpose to form a combined wave-beam. The divergences and intensities of the constituent wave-beams are selected such that the combined wave-beam has a desired substantially constant extent over a desired range of distances along said propagation axes.