Abstract: A system operating in a vehicle includes a lidar module, a camera, and a controller communicatively coupled to the camera and the lidar module. The lidar module includes: a light source configured to emit pulses of light, a scanner configured to direct the emitted pulses of light in accordance with a scan pattern to illuminate a field of regard of the lidar module, and a receiver configured to detect the emitted pulses of light scattered by one or more remote objects to capture a set of lidar pixels of a scan frame, in a sequence defined by the scan pattern. The camera has a field of view that at least partially overlaps the field of regard of the lidar module. The controller is configured to cause the camera to capture multiple images while the receiver of the lidar module captures the set of lidar pixels of the scan frame.

Abstract: A lidar system includes a light source configured to emit light pulses and a receiver configured to detect light from some of the light pulses scattered by remote targets. The receiver includes an avalanche photodiode operating in the linear mode for detecting the light pulses. To prevent damage to the linear mode avalanche photodiode a quench circuit is coupled to the avalanche photodiode, where the quench circuit reduces a bias voltage applied to the avalanche photodiode, when an avalanche event occurs at the avalanche photodiode.

Abstract: In one embodiment, a lidar system includes a light source configured to emit an optical signal and a receiver that includes one or more detectors configured to detect a portion of the emitted optical signal scattered by a target located a distance from the lidar system. The lidar system also includes a photonic integrated circuit (PIC) that includes an input optical element configured to receive the portion of the scattered optical signal and couple the portion of the scattered optical signal into an input optical waveguide. The input optical waveguide is one of one or more optical waveguides of the PIC configured to convey the portion of the scattered optical signal to the one or more detectors of the receiver. The lidar system further includes a processor configured to determine the distance from the lidar system to the target.

Abstract: In one embodiment, a lidar system includes a light source configured to emit pulses of light and a scanner configured to scan the emitted pulses of light across a field of regard of the lidar system. The lidar system also includes a receiver configured to detect a portion of the emitted pulses of light scattered by a target located a distance from the lidar system. The receiver includes an aluminum-indium-arsenide-antimonide (AlInAsSb) avalanche photodiode (APD) configured to: receive a pulse of light of the portion of the emitted pulses of light scattered by the target and produce an electrical-current pulse corresponding to the received pulse of light. The lidar system further includes a processor configured to determine the distance from the lidar system to the target based at least in part on a round-trip time of flight for the received pulse of light.

Abstract: A lidar system comprising with a light source, an optical link, and a sensor head. The light source can include a seed laser to produce pulses of light and an optical preamplifier to amplify the pulses of light. The optical link can convey amplified pulses of light to the sensor head remotely located from the light source. The sensor head can include an optical booster amplifier, a scanner to scan amplified output pulses of light across a field of regard, and a receiver to detect pulses of light scattered by a target located a distance from the sensor head.

Abstract: A lidar system includes one or more light sources configured to emit light pulses, a scanner configured to direct the emitted light pulses as beams along one or more scan directions to illuminate, for each orientation of the scanner with each of the plurality of beams, a respective light-source field of view corresponding to a respective pixel, and a receiver configured to detect the light pulses scattered by one or more remote targets. The receiver includes a first, second, and third detectors to detect light pulses associated with respective beams. Each detector has a separate detector field of view within which the detector receives scattered light. A spatial separation between the first detector and the second detector is greater than a spatial separation between the second detector and the third detector.

Abstract: A lidar system comprises a light source configured to emit pulses of light, a scanner configured to direct the pulses of light along a scan direction, where each of the pulses of light illuminates a respective field of view of the light source, and a receiver configured to detect the pulses of light scattered by remote targets. The receiver includes a low-gain detector associated with a low gain and a high-gain detector associated with a high gain. The low-gain detector is positioned so that a first scattered pulse of light that returns from a first target, located closer to the receiver than a second target, is detected primarily by the low-gain detector, and a second scattered pulse of light that returns from the second target is detected primarily by the high-gain detector.

Abstract: In one embodiment, a lidar system includes a light source configured to emit an optical signal. The light source includes a seed laser diode configured to produce a seed optical signal and a semiconductor optical amplifier (SOA) configured to amplify the seed optical signal to produce an amplified seed optical signal, where the emitted optical signal includes the amplified seed optical signal. The light source further includes an electronic driver configured to supply electrical current to the seed laser diode and electrical current to the SOA. The lidar system also includes a receiver configured to detect a portion of the emitted optical signal scattered by a target located a distance from the lidar system. The lidar system further includes a processor configured to determine the distance from the lidar system to the target.

Abstract: 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.

Abstract: In one embodiment, a lidar system includes a light source configured to emit (i) local-oscillator light and (ii) pulses of light, where each emitted pulse of light is coherent with a corresponding portion of the local-oscillator light. 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 that is scattered by a target located a distance from the lidar system. The local-oscillator light and the received pulse of light are coherently mixed together at the receiver. The lidar system further includes a processor configured to determine the distance to the target based at least in part on a time-of-arrival for the received pulse of light.

Abstract: In one embodiment, a lidar system includes a light source configured to emit (i) local-oscillator light and (ii) pulses of light, where each emitted pulse of light is coherent with a corresponding portion of the local-oscillator light. The light source includes a seed laser configured to produce seed light and the local-oscillator light. The light source also includes a pulsed optical amplifier configured to amplify temporal portions of the seed light to produce the emitted pulses of light, where each amplified temporal portion of the seed light corresponds to one of the emitted pulses of light. 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 that is scattered by a target located a distance from the lidar system.

Abstract: In one embodiment, a lidar system includes a light source configured to emit an optical signal. The light source includes a seed laser diode configured to produce a seed optical signal and a semiconductor optical amplifier (SOA) configured to amplify the seed optical signal to produce an amplified seed optical signal, where the emitted optical signal includes the amplified seed optical signal. The lidar system also includes a scanner configured to direct the emitted optical signal into a field of regard of the lidar system and a receiver configured to detect a portion of the emitted optical signal scattered by a target located a distance from the lidar system. The lidar system further includes a processor configured to determine the distance from the lidar system to the target.

Abstract: In one embodiment, a lidar system includes a light source configured to emit (i) local-oscillator light and (ii) pulses of light, where each emitted pulse of light is coherent with a corresponding portion of the local-oscillator light. 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 comprising light from one of the emitted pulses of light that is scattered by a target located a distance from the lidar system. The local-oscillator light and the received pulse of light are coherently mixed together at the receiver. The receiver includes one or more detectors configured to produce one or more respective photocurrent signals corresponding to the coherent mixing of the local-oscillator light and the received pulse of light. The receiver also includes a pulse-detection circuit configured to determine a time-of-arrival for the received pulse of light.

Abstract: A system operating in a vehicle includes a lidar module, a camera, and a controller communicatively coupled to the camera and the lidar module. The lidar module includes: a light source configured to emit pulses of light, a scanner configured to direct the emitted pulses of light in accordance with a scan pattern to illuminate a field of regard of the lidar module, and a receiver configured to detect the emitted pulses of light scattered by one or more remote objects to capture a set of lidar pixels of a scan frame, in a sequence defined by the scan pattern. The camera has a field of view that at least partially overlaps the field of regard of the lidar module. The controller is configured to cause the camera to capture multiple images while the receiver of the lidar module captures the set of lidar pixels of the scan frame.

Abstract: In one embodiment, a lidar system includes a light source configured to emit a pulse of light and a scanner configured to direct the emitted pulse of light into a field of regard of the lidar system. The lidar system also includes a receiver configured to receive a portion of the emitted pulse of light scattered by a target located a distance from the lidar system. The receiver includes a digital micromirror device (DMD) that includes a two-dimensional array of electrically addressable micromirrors, where a portion of the micromirrors are configured to be set to an active-on state to direct the received pulse of light to a detector array. The detector array includes a two-dimensional array of detector elements, where the detector array is configured to detect the received pulse of light and produce an electrical signal corresponding to the received pulse of light.

Abstract: A detector system within a lidar receiver is configured to compensate for range walk error by detecting both the rising edge and the falling edge of a received light pulse as the envelope of the received light pulse passes through a particular detection (magnitude) threshold. Detection circuitry within the detector system then determines the center of the received light pulse as the point equidistant in time between the detected rising and falling edges of the received light pulse, and uses the time associated with the center of the received light pulse to determine the range to the target from which the scattered light pulse was received.

Abstract: A lidar system includes a transmitter that encodes successive transmit pulses with different pulse characteristics and a receiver that detects the pulse characteristics of each received (scattered or reflected) pulse and that distinguishes between the received pulses based on the detected pulse characteristics. The lidar system thus resolves range ambiguities by encoding pulses of scan positions in the same or different scan periods to have different pulse characteristics, such as different pulse widths or different pulse envelope shapes. The receiver includes a pulse decoder configured to detect the relevant pulse characteristics of the received pulse and a resolver that determines if the pulse characteristics of the received pulse matches the pulse characteristics of the current scan position or that of a previous scan position.

Abstract: A system includes a lidar, a camera, and a controller communicatively coupled to the camera and the lidar. The lidar includes a laser configured to emit pulses of light, a scanner configured to direct the emitted pulses in accordance with a scan pattern, and a receiver configured to detect the emitted pulse of light scattered by one or more remote targets to collect a set of lidar pixels of a scan frame, in a sequence defined by the scan pattern. The camera has a field of regard that at least partially overlaps the field of regard of the lidar. The controller is configured to cause the camera to capture images while the receiver of the lidar module collects the complete set of lidar pixels of the scan frame, and align lidar pixels with corresponding pixels in the captured images.

Abstract: A lidar system includes a lighting module configured to (i) select a wavelength from among a plurality of wavelength values, for a particular time period, and (ii) emit light at the selected wavelength. The lighting module emits light at different wavelengths during at least two adjacent periods of time. The lidar system further includes a scanner configured to direct the pulse of light to illuminate a respective region within a field of regard of the lidar system and a receiver module configured to (i) receive a light signal and (ii) determine whether the received light signal includes the light emitted by the lighting module and scattered by a remote target, based at least in part on the wavelength selected by the lighting module.

Abstract: To decrease the likelihood of a false detection when detecting light from light pulses scattered by remote targets in a lidar system, a receiver in the lidar system includes a photodetector and a pulse-detection circuit having a gain circuit with a varying amount of gain over time. The gain circuit operates in a low-gain mode for a time period T1 beginning with time t0 when a light pulse is emitted to prevent the receiver from detecting return light pulses during the threshold time period T1. Upon expiration of the threshold time period T1, the gain circuit operates in a high-gain mode to begin detecting return light pulses until a subsequent light pulse is emitted.