Abstract: The present disclosure relates to optical devices and systems, specifically those related to light detection and ranging (LIDAR) systems. An example device includes a shaft defining a rotational axis. The shaft includes a first material having a first coefficient of thermal expansion. The device also includes a rotatable mirror disposed about the shaft. The rotatable mirror includes a multi-sided structure having an exterior surface and an interior surface. The multi-sided structure includes a second material having a second coefficient of thermal expansion. The second coefficient of thermal expansion is different from the first coefficient of thermal expansion. The multi-sided structure also includes a plurality of reflective surfaces disposed on the exterior surface of the multi-sided structure. The multi-sided structure yet further includes one or more support members coupled to the interior surface and the shaft.

Abstract: The present disclosure relates to devices, lidar systems, and vehicles that include optical redirectors. An example lidar system includes a transmitter and a receiver. The transmitter includes at least one light-emitter device configured to transmit emission light into an environment. The receiver is configured to detect return light from the environment and includes a plurality of apertures, a plurality of photodetectors, and a plurality of optical redirectors. Each optical redirector is configured to optically couple a respective portion of return light from a respective aperture to at least one photodetector of the plurality of photodetectors. Each optical redirector also has a rotational orientation relative to other optical redirectors such that the redirection paths of optical redirectors that correspond to adjacent apertures are not coplanar with one another.

Abstract: One example system includes a first light detection and ranging (LIDAR) device that scans a first field-of-view defined by a first range of pointing directions associated with the first LIDAR device. The system also includes a second LIDAR device that scans a second FOV defined by a second range of pointing directions associated with the second LIDAR device. The second FOV at least partially overlaps the first FOV. The system also includes a first controller that adjusts a first pointing direction of the first LIDAR device. The system also includes a second controller that adjusts a second pointing direction of the second LIDAR device synchronously with the adjustment of the first pointing direction of the first LIDAR device.

Abstract: Example embodiments relate to LIDAR systems with multi-faceted mirrors. An example embodiment includes a LIDAR system. The system includes a multi-faceted mirror that includes a plurality of reflective facets, which rotates about a first rotational axis. The system also includes a light emitter configured to emit a light signal toward one or more regions of a scene. Further, the system includes a light detector configured to detect a reflected light signal. In addition, the system includes an optical window positioned between the multi-faceted mirror and the one or more regions of the scene such that light reflected from one or more of the reflective facets is transmitted through the optical window. The optical window is positioned such that the optical window is non-perpendicular to the direction toward which the light emitted along the optical axis is directed for all angles of the multi-faceted mirror.

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 optical devices and systems, specifically those related to light detection and ranging (LIDAR) systems. An example device includes a shaft defining a rotational axis. The shaft includes a first material having a first coefficient of thermal expansion. The device also includes a rotatable mirror disposed about the shaft. The rotatable mirror includes a multi-sided structure having an exterior surface and an interior surface. The multi-sided structure includes a second material having a second coefficient of thermal expansion. The second coefficient of thermal expansion is different from the first coefficient of thermal expansion. The multi-sided structure also includes a plurality of reflective surfaces disposed on the exterior surface of the multi-sided structure. The multi-sided structure yet further includes one or more support members coupled to the interior surface and the shaft.

Abstract: The present disclosure relates to optical systems, specifically light detection and ranging (LIDAR) systems. An example optical system includes a laser light source operable to emit laser light along a first axis and a mirror element with a plurality of reflective surfaces. The mirror element is configured to rotate about a second axis. The plurality of reflective surfaces is disposed about the second axis. The mirror element and the laser light source are coupled to a base structure, which is configured to rotate about a third axis. While the rotational angle of the mirror element is within an angular range, the emitted laser light interacts with both a first reflective surface and a second reflective surface of the plurality of reflective surfaces and is reflected into the environment by the first and second reflective surfaces.

Abstract: The present disclosure relates to systems, methods, and vehicles that facilitate a light detection and ranging (LIDAR or lidar) system that may take advantage of “dead angles” where the lidar system is oriented toward support structure or another “uninteresting” feature. In such scenarios, light pulses may be redirected toward more-interesting features in the environment. An example system includes a lidar system configured to emit light pulses into an environment of the system so as to provide information indicative of objects within a default field of view. The system also includes a reflective surface optically coupled to the lidar system. The reflective surface is configured to reflect at least a portion of the emitted light pulses so as to provide an extended field of view. The lidar system is further configured to provide information indicative of objects within the extended field of view.

Abstract: Example embodiments relate to spinning lidars utilizing one or more secondary mirrors. An example embodiment includes a lidar system that includes a rotatable portion. The rotatable portion includes one or more light sources and one or more one or more detectors. The rotatable portion is configured to rotate about a rotational axis such that the one or more light sources are operable to emit light within an azimuthal 360 degree field of view. The 360 degree field of view comprises a primary field of view that is less than 360 degrees. The lidar system also includes at least one secondary mirror configured to reflect light initially emitted by the one or more light sources in a direction away from the primary field of view so as to redirect the light into a secondary field of view.

Abstract: Aspects of the technology employ sensors having high speed rotating mirror assemblies. For instance, the sensors may be Lidar sensors configured to detect people and other objects in an area of interest. A given mirror assembly may have a triangular or other geometric cross-sectional shape. The reflective faces of the mirror assembly may connect along edges or corners. In order to minimize wind drag and torque issues, the corners are rounded, filleted, beveled, chamfered or otherwise truncated. Such truncation may extend the length of the mirror side. The mirror assembly may employ one or more beam stops, light baffles and/or acoustic/aerodynamic baffles. These sensors may be employed with self-driving or manual driven vehicles or other equipment. The sensors may also be used in and around buildings.

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 beam homogenization for occlusion avoidance. One embodiment includes a light detection and ranging (LIDAR) device. The LIDAR device includes a transmitter and a receiver. The transmitter includes a light emitter. The light emitter emits light that diverges along a fast-axis and a slow-axis. The transmitter also includes a fast-axis collimation (FAC) lens optically coupled to the light emitter. The FAC lens is configured to receive light emitted by the light emitter and reduce a divergence of the received light along the fast-axis of the light emitter to provide reduced-divergence light. The transmitter further includes a transmit lens optically coupled to the FAC lens. The transmit lens is configured to receive the reduced-divergence light from the FAC lens and provide transmit light. The FAC lens is positioned relative to the light emitter such that the reduced-divergence light is expanded at the transmit lens.

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: The present disclosure relates to systems, methods, and vehicles that facilitate a light detection and ranging (LIDAR or lidar) system that may take advantage of “dead angles” where the lidar system is oriented toward support structure or another “uninteresting” feature. In such scenarios, light pulses may be redirected toward more-interesting features in the environment. An example system includes a lidar system configured to emit light pulses into an environment of the system so as to provide information indicative of objects within a default field of view. The system also includes a reflective surface optically coupled to the lidar system. The reflective surface is configured to reflect at least a portion of the emitted light pulses so as to provide an extended field of view. The lidar system is further configured to provide information indicative of objects within the extended field of view.

Abstract: An example lidar system includes a housing defining an interior space. The housing includes at least one optical window. The lidar system also includes a rotatable mirror assembly disposed within the interior space. The rotatable mirror assembly includes a transmit mirror portion and a receive mirror portion. The lidar system additionally includes a transmitter disposed within the interior space. The transmitter is configured to emit emission light into an environment of the lidar system along a transmit path. The lidar system also includes a receiver disposed within the interior space. The receiver is configured to detect return light that is received from the environment along a receive path. The lidar system additionally includes at least one optical baffle configured to minimize stray light in the interior space.

Abstract: Example implementations may relate to determining a strategy for a drop process associated with a light detection and ranging (LIDAR) device. In particular, the LIDAR device could emit light pulses and detect return light pulses, and could generate a set of data points representative of the detected return light pulses. The drop process could involve a computing system discarding data point(s) of the set and/or preventing emission of light pulse(s) by the LIDAR device. Accordingly, the computing system could detect a trigger to engage in the drop process, and may responsively (i) use information associated with the environment around the vehicle, operation of the vehicle, and/or operation of the LIDAR device as a basis to determine the strategy for the drop process, and (ii) engage in the drop process in accordance with the determined strategy.

Abstract: The present disclosure relates to systems and methods that facilitate a scanning light detection and ranging (LIDAR) device configured to provide an asymmetric illumination pattern. An example system includes a rotatable base configured to rotate about a first axis and a mirror assembly. The mirror assembly is configured to rotate about a second axis, which is substantially perpendicular to the first axis. The system also includes an optical cavity coupled to the rotatable base. The optical cavity includes a photodetector and a photodetector lens arranged so as to define a light-receiving axis. The optical cavity also includes a light-emitter device and a light-emitter lens arranged so as to define a light-emission axis. At least one of the light-receiving axis or the light-emission axis forms a tilt angle with respect to the first axis.

Abstract: The present disclosure relates to systems and methods that facilitate compliance of a laser device with a laser safety threshold. An example method includes receiving, from a sensing circuit, an operating voltage that is indicative of a charge of a capacitive element of a laser pulser circuit. The method also includes comparing a first voltage indicative of the operating voltage and a second voltage indicative of a reference voltage. The method additionally includes providing an output value based on the comparing. The method yet further includes evaluating compliance with the laser safety threshold based on the output value.

Abstract: One example system includes a first light detection and ranging (LIDAR) device that scans a first field-of-view defined by a first range of pointing directions associated with the first LIDAR device. The system also includes a second LIDAR device that scans a second FOV defined by a second range of pointing directions associated with the second LIDAR device. The second FOV at least partially overlaps the first FOV. The system also includes a first controller that adjusts a first pointing direction of the first LIDAR device. The system also includes a second controller that adjusts a second pointing direction of the second LIDAR device synchronously with the adjustment of the first pointing direction of the first LIDAR device.