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: An optical system may include a substrate and a plurality of silicon photomultipliers (SiPMs) monolithically integrated with the substrate. Each SiPM may include a plurality of single photon avalanche diodes (SPADs). The optical system also includes an aperture array having a plurality of apertures. The plurality of SiPMs and the aperture array are aligned so as to define a plurality of receiver channels. Each receiver channel includes a respective SiPM of the plurality of SiPMs optically coupled to a respective aperture of the plurality of apertures.

Abstract: The present disclosure relates to devices, systems, and methods relating to configurable silicon photomultiplier (SiPM) devices. An example device includes a substrate and a plurality of single photon avalanche diodes (SPADs) coupled to the substrate. The device also includes a plurality of outputs coupled to the substrate and a plurality of electrical components coupled to the substrate. The plurality of electrical components are configured to selectively connect the plurality of SPADs to the plurality of outputs by selecting which output of the plurality of outputs is connected to each SPAD of the plurality of SPADs and to thereby define a plurality of SiPMs in the device such that each SiPM of the plurality of SiPMs comprises a respective set of one or more SPADs connected to a respective output of the plurality of outputs.

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: An example method and system for filtering point cloud data includes obtaining point cloud data from a LIDAR device. The point cloud data may include at least a first pulse-length range and a second pulse-length range. The first range may include one or more first-length pulses and the second range may include one or more second-length pulses. The method may further include filtering the point cloud data by determining respective magnitudes of each of the one or more first-length pulses and each of the one or more second-length pulses, comparing the magnitudes of the first-length pulses to a first threshold, comparing the magnitudes of the second-length pulses to a second threshold, and removing any pulses having a magnitude less than the respective thresholds. The method may further include determining, based on the filtered point cloud data, objects in an environment around the LIDAR.

Abstract: An optical system may include a substrate and a plurality of silicon photomultipliers (SiPMs) monolithically integrated with the substrate. Each SiPM may include a plurality of single photon avalanche diodes (SPADs). The optical system also includes an aperture array having a plurality of apertures. The plurality of SiPMs and the aperture array are aligned so as to define a plurality of receiver channels. Each receiver channel includes a respective SiPM of the plurality of SiPMs optically coupled to a respective aperture of the plurality of apertures.

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, systems, and methods relating to configurable silicon photomultiplier (SiPM) devices. An example device includes a substrate and a plurality of single photon avalanche diodes (SPADs) coupled to the substrate. The device also includes a plurality of outputs coupled to the substrate and a plurality of electrical components coupled to the substrate. The plurality of electrical components are configured to selectively connect the plurality of SPADs to the plurality of outputs by selecting which output of the plurality of outputs is connected to each SPAD of the plurality of SPADs and to thereby define a plurality of SiPMs in the device such that each SiPM of the plurality of SiPMs comprises a respective set of one or more SPADs connected to a respective output of the plurality of outputs.

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: A system includes a near-infrared (NIR) illuminator, an NIR image sensor, a light detection and ranging (LIDAR) device, and control circuitry configured to perform operations. The operations include causing the NIR illuminator to illuminate a portion of an environment, and obtaining, from the NIR image sensor, NIR image data representing the portion of the environment illuminated by the NIR illuminator. The operations also include detecting a retroreflector within the NIR image data and, based on detecting the retroreflector within the NIR image, determining a position of the retroreflector within the environment. The operations further include, based on the position of the retroreflector within the environment, adjusting at least one parameter of the LIDAR device in connection with scanning the retroreflector.

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: 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: 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: 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 using cleaning protocols to monitor defects associated with light detection and ranging (lidar) devices. An example embodiment includes a method. The method includes applying, using a cleaning device, a cleaning protocol to one or more optical components of a light detection and ranging (lidar) device. The method also includes emitting, from a light emitter of the lidar device, one or more light signals. Additionally, the method includes detecting, by a light detector of the lidar device, reflections of the one or more light signals. Further, the method includes determining, by a controller of the lidar device based on the detected reflections of the one or more light signals, that one or more defects are present within the one or more optical components or within the cleaning device.

Abstract: Example embodiments relate to differential methods for determining environment estimation, lidar impairment detection, and filtering. An example embodiment includes dividing a plurality of lidar device channels into a first group and a second group and interleaving the channels. The embodiment includes applying a threshold to the first group. The embodiment further includes emitting light pulses from a lidar device into an environment surrounding the lidar device, and detecting return light pulses. The return light pulses in the first group of channels are sampled from the signals that exceed the threshold. The embodiment may further include determining a differential in a statistical distribution between the return light pulses in the first group and the return light pulses in the second group. Based on the differential, the method can include detecting an atmospheric scattering medium in the environment surrounding the lidar device.

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 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.