Abstract: The present disclosure relates to devices, light detection and ranging (lidar) systems, and vehicles involving solid-state, single photon detectors. An example device includes a substrate defining a primary plane and a plurality of photodetector cells disposed along the primary plane. The plurality of photodetector cells includes at least one large-area cell and at least one small-area cell. The large-area cell has a first area and the small-area cell has a second area and the first area is greater than the second area. The device also includes read out circuitry coupled to the plurality of photodetector cells. The read out circuitry is configured to provide an output signal based on incident light detected by the plurality of photodetector cells.

Abstract: Described herein is a LIDAR device that may include a transmitter, first and second receivers, and a rotating platform. The transmitter may be configured to emit light having a vertical beam width. The first receiver may be configured to detect light at a first resolution while scanning the environment with a first FOV and the second receiver may be configured to detect light at a second resolution while scanning the environment with a second FOV. In this arrangement, the first resolution may be higher than the second resolution, the first FOV may be at least partially different from the second FOV, and the vertical beam width may encompass at least a vertical extent of the first and second FOVs. Further, the rotating platform may be configured to rotate about an axis such that the transmitter and first and second receivers each move based on the rotation.

Abstract: The present disclosure relates to limitation of noise on light detectors using an aperture. One example embodiment includes a system. The system includes a lens disposed relative to a scene and configured to focus light from the scene onto a focal plane. The system also includes an aperture defined within an opaque material disposed at the focal plane of the lens. The aperture has a cross-sectional area. In addition, the system includes an array of light detectors disposed on a side of the focal plane opposite the lens and configured to intercept and detect diverging light focused by the lens and transmitted through the aperture. A cross-sectional area of the array of light detectors that intercepts the diverging light is greater than the cross-sectional area of the aperture.

Abstract: The present disclosure relates to devices, light detection and ranging (lidar) systems, and vehicles involving solid-state, single photon detectors. An example device includes a substrate defining a primary plane and a plurality of photodetector cells disposed along the primary plane. The plurality of photodetector cells includes at least one large-area cell and at least one small-area cell. The large-area cell has a first area and the small-area cell has a second area and the first area is greater than the second area. The device also includes read out circuitry coupled to the plurality of photodetector cells. The read out circuitry is configured to provide an output signal based on incident light detected by the plurality of photodetector cells.

Abstract: Described herein is a LIDAR device that may include a transmitter, first and second receivers, and a rotating platform. The transmitter may be configured to emit light having a vertical beam width. The first receiver may be configured to detect light at a first resolution while scanning the environment with a first FOV and the second receiver may be configured to detect light at a second resolution while scanning the environment with a second FOV. In this arrangement, the first resolution may be higher than the second resolution, the first FOV may be at least partially different from the second FOV, and the vertical beam width may encompass at least a vertical extent of the first and second FOVs. Further, the rotating platform may be configured to rotate about an axis such that the transmitter and first and second receivers each move based on the rotation.

Abstract: Example embodiments relate to light detectors for nearby object detection in light detection and ranging (lidar) devices. An example embodiment includes a lidar device. The lidar device includes a light emitter configured to emit a light signal at a first time. The lidar device also includes a light detector configured to detect the emitted light signal. Additionally, the lidar device includes a biasing circuit configured to modify a detector bias using a bias signal. The bias signal ramps the detector bias from a first bias level at the first time to a second bias level at a second time. The second time is separated from the first time by a ramp duration. The ramp duration is sufficient to prevent any internal feedback within the lidar device caused by the emitted light signal from saturating the light detector or detection circuitry associated with the light detector.

Abstract: One example method involves a light detection and ranging (LIDAR) device focusing light from a target region in a scene for receipt by a detector. The method also involves emitting a primary light pulse. The method also involves directing, via one or more optical elements, the primary light pulse toward the target region. The primary light pulse illuminates the target region according to a primary light intensity of the primary light pulse. The method also involves emitting a secondary light pulse. At least a portion of the secondary light pulse illuminates the target region according to a secondary light intensity of the secondary light pulse. The secondary light intensity is less than the primary light intensity.

Abstract: Example embodiments relate to pulse energy plans for light detection and ranging (lidar) devices based on areas of interest and thermal budgets. An example lidar device includes a plurality of light emitters configured to emit light pulses into an environment in a plurality of different emission directions. The lidar device also includes circuitry configured to power the plurality of light emitters. Further, the lidar device includes a plurality of detectors configured to detect reflections of light pulses emitted by the plurality of light emitters. In addition, the lidar device includes a controller configured to (i) determine a pulse energy plan based on one or more regions of interest in the environment and a thermal budget and (ii) control the circuitry based on the pulse energy plan. The pulse energy plan specifies a pulse energy level for each light pulse emitted by each light emitter in the plurality of light emitters.

Abstract: The present disclosure relates to methods and systems that improve the dynamic range of LIDAR systems. An example system includes a plurality of single-photon photodetectors and at least one additional photodetector monolithically integrated on a shared substrate. The plurality of single-photon photodetectors and the at least one additional photodetector are configured to detect light from a shared field of view. The system also includes a controller configured to carry out operations. The operations include: receiving respective photodetector signals from the plurality of single-photon photodetectors and the at least one additional photodetector; selecting a photodetector signal from at least two of: the two received photodetector signals and a combined photodetector signal formed by combining the two received photodetector signals; and determining an intensity of light in the field of view based on the selected photodetector signal.

Abstract: Example embodiments relate to calibration systems for light detection and ranging (lidar) devices. An example calibration system includes a calibration target that includes a surface having at least one characterized reflectivity. The surface is configured to receive one or more calibration signals emitted by a lidar device along one or more optical axes when the lidar device is separated from the calibration target by an adjustable distance. The calibration system also includes at least one lens that modifies the one or more calibration signals. In addition, the system includes an adjustable attenuator configured to attenuate each of the one or more calibration signals to simulate, in combination with the at least one lens, a distance that is greater than the adjustable distance. Further, the system includes a calibration controller configured to analyze data associated with detected reflections of the one or more calibration signals.

Abstract: Example embodiments relate to pulse energy plans for light detection and ranging (lidar) devices based on areas of interest and thermal budgets. An example lidar device includes a plurality of light emitters configured to emit light pulses into an environment in a plurality of different emission directions. The lidar device also includes circuitry configured to power the plurality of light emitters. Further, the lidar device includes a plurality of detectors configured to detect reflections of light pulses emitted by the plurality of light emitters. In addition, the lidar device includes a controller configured to (i) determine a pulse energy plan based on one or more regions of interest in the environment and a thermal budget and (ii) control the circuitry based on the pulse energy plan. The pulse energy plan specifies a pulse energy level for each light pulse emitted by each light emitter in the plurality of light emitters.

Abstract: The present disclosure relates to systems and methods that provide both an image of a scene and depth information for the scene. An example system includes at least one time-of-flight (ToF) sensor and an imaging sensor. The ToF sensor and the imaging sensor are configured to receive light from a scene. The system also includes at least one light source and a controller that carries out operations. The operations include causing the at least one light source to illuminate at least a portion of the scene with illumination light according to an illumination schedule. The operations also include causing the at least one ToF sensor to provide information indicative of a depth map of the scene based on the illumination light. The operations additionally include causing the imaging sensor to provide information indicative of an image of the scene based on the illumination light.

Abstract: The present disclosure relates to systems and methods that include a monolithic, single-chip receiver. An example system includes a plurality of macropixels, each made up of an array of single photon avalanche diodes (SPADs). The system also includes a plurality of pipelined adders communicatively coupled to a respective portion of the plurality of macropixels. The system additionally includes a controller configured to carry out operations. The operations include during a listening period, receiving, at each pipelined adder of the plurality of pipelined adders, respective photosignals from the respective portion of the plurality of macropixels. The operations also include causing each pipelined adder of the plurality of pipelined adders to provide an output that includes a series of frames that provide an average number of SPADs of the respective portion of the plurality of macropixels that were triggered during a given listening period.

Abstract: Example embodiments relate to controlling detection time in photodetectors. An example embodiment includes a device. The device includes a substrate. The device also includes a photodetector coupled to the substrate. The photodetector is arranged to detect light emitted from a light source that irradiates a top surface of the device. A depth of the substrate is at most 100 times a diffusion length of a minority carrier within the substrate so as to mitigate dark current arising from minority carriers photoexcited in the substrate based on the light emitted from the light source.

Abstract: An example method includes receiving point cloud information about a field of view of a lidar system. The point cloud information includes spatiotemporal and amplitude information about return light received. The method also includes determining, based on the point cloud information, a set of bright light returns from at least one highly reflective object. The bright light returns include return light having an amplitude above a photon threshold and a corresponding bright light return range. The method yet further includes determining, based on the point cloud information, a set of crosstalk returns. The crosstalk returns include return light having a corresponding crosstalk return range. The method includes adjusting, based on a normalized number of crosstalk returns, at least one of: a cleaning system, an operating mode of a lidar system, or an operating mode of a vehicle.

Abstract: The present disclosure relates to limitation of noise on light detectors using an aperture. One example embodiment includes a system. The system includes a lens disposed relative to a scene and configured to focus light from the scene onto a focal plane. The system also includes an aperture defined within an opaque material disposed at the focal plane of the lens. The aperture has a cross-sectional area. In addition, the system includes an array of light detectors disposed on a side of the focal plane opposite the lens and configured to intercept and detect diverging light focused by the lens and transmitted through the aperture. A cross-sectional area of the array of light detectors that intercepts the diverging light is greater than the cross-sectional area of the aperture.

Abstract: The present disclosure relates to systems and methods that provide both an image of a scene and depth information for the scene. An example system includes at least one time-of-flight (ToF) sensor and an imaging sensor. The ToF sensor and the imaging sensor are configured to receive light from a scene. The system also includes at least one light source and a controller that carries out operations. The operations include causing the at least one light source to illuminate at least a portion of the scene with illumination light according to an illumination schedule. The operations also include causing the at least one ToF sensor to provide information indicative of a depth map of the scene based on the illumination light. The operations additionally include causing the imaging sensor to provide information indicative of an image of the scene based on the illumination light.

Abstract: Example embodiments relate to controlling detection time in photodetectors. An example embodiment includes a device. The device includes a substrate. The device also includes a photodetector coupled to the substrate. The photodetector is arranged to detect light emitted from a light source that irradiates a top surface of the device. A depth of the substrate is at most 100 times a diffusion length of a minority carrier within the substrate so as to mitigate dark current arising from minority carriers photoexcited in the substrate based on the light emitted from the light source.

Abstract: The present disclosure relates to light detection and ranging (lidar) systems, lidar-equipped vehicles, and associated methods. An example method includes causing a firing circuit to trigger emission of an initial group of detection pulses from at least one light-emitter device of a lidar system in accordance with an initial set of one or more light-emission parameters. The method also includes causing the firing circuit to trigger emission of one or more test pulses and receiving, from at least one detector, information indicative of one or more return test pulses. The method yet further includes determining, based on the received information, a presence of a retroreflector based on an intensity of the return test pulse. The method additionally includes determining a subsequent set of light-emission parameters and causing the firing circuit to trigger emission of a subsequent group of detection pulses in accordance with the subsequent set of light-emission parameters.

Abstract: The present disclosure relates to limitation of noise on light detectors using an aperture. One example embodiment includes a system. The system includes a lens disposed relative to a scene and configured to focus light from the scene onto a focal plane. The system also includes an aperture defined within an opaque material disposed at the focal plane of the lens. The aperture has a cross-sectional area. In addition, the system includes an array of light detectors disposed on a side of the focal plane opposite the lens and configured to intercept and detect diverging light focused by the lens and transmitted through the aperture. A cross-sectional area of the array of light detectors that intercepts the diverging light is greater than the cross-sectional area of the aperture.