Abstract: A waveguide grating antenna apparatus includes a substrate layer, a lower waveguide array layer upon the substrate, and an upper waveguide array layer positioned above the lower waveguide array layer. The lower waveguide array layer is composed of a plurality of first waveguides extending axially and a plurality of second waveguides extending axially and arranged in parallel and alternating in position with the plurality of first waveguides across the lower waveguide array layer. Each first waveguide is of a first maximum width. Each second waveguide is of a second maximum width narrower than the first maximum width and is spaced apart from each adjacent first waveguide. The upper waveguide array layer is composed of adjacent, separated elements extending axially along each first waveguide and each second waveguide.

Abstract: First training sensor data detected by a plurality of real-world sensors are obtained. The first training sensor data is associated with physical environment conditions. Second training sensor data detected by a plurality of virtual sensors are obtained. The second training sensor data is associated with simulated physical conditions of a virtual environment. A machine learning model is trained using both real-world and virtual training datasets including the first training sensor data, the second training sensor data, and respective sensor setting parameters of the plurality of real-world sensors and the plurality of virtual sensors. The real-world and virtual training datasets used to train the machine learning model include indications associated with the respective sensor parameter settings including one or more of the following: different scan line settings or different exposure settings.

Abstract: An optical receiver includes a parasitic current compensation circuit having a reference diode, a sense avalanche photodiode (APD), at least one DC voltage source, and a measurement node. The at least one DC voltage source is configured to generate a first DC bias voltage that varies over time and drives the reference diode, and generates a second DC bias voltage that varies over time and drives the sense APD. A reference parasitic current travels through the reference diode based on the first DC bias voltage. A sense current travels through the sense APD based on the second DC bias voltage and exposure of the sense APD to a light signal. The measurement node receives a sense photocurrent, which is generated by the sense APD in response to the exposure of the sense APD to the light signal, the sense photocurrent including the sense current less the reference parasitic current.

Abstract: A scanner for a lidar system is configured to direct emitted light to scan a field of regard of the lidar system in accordance with a scan pattern. The scanner includes a mirror and an actuator assembly. The mirror includes a reflective surface and a rear surface and is pivotable along a mirror axle. The actuator assembly is disposed along the rear surface of the mirror and is configured to exert a torque on the mirror to cause the mirror to pivot about the mirror axle.

Abstract: Method and apparatus for generating pulses in a light detection and ranging (LiDAR) system. In some embodiments, a resonance chamber is provided to recirculate electromagnetic radiation from a light source between a base mirror and an active laminated structure characterized as a Bragg grating structure and having interleaved passive and active layers. A Q-switch control circuit applies a voltage profile to the active layers to transition the active laminated structure between a charging state in which the electromagnetic radiation recirculates within the resonance chamber and a release state in which the electromagnetic radiation is transmitted through the active laminated structure as an emitted light pulse. The passive layers may be formed of a dielectric material. The active layers may be formed of a metal material such but not limited to Indium Tin Oxide (ITO), Lithium Niobate (LiNbO3), Barium Titanate (BaTiO3), doped Silicon (Si), or doped Germanium (Ge).

Abstract: A light detection and ranging system can have a metasurface that continuously extends between a pair of electrical contacts. The metasurface may be separated from an underlying silicon substrate by an air gap with the silicon substate doped with a P-i-N configuration to create electrostatic force that alters a size of the air gap in response to a voltage bias between the pair of electrical contacts.

Abstract: A system includes a signal transmitter configured to emit a signal pulse and a signal receiver configured to receive one or more reflected pulses of the emitted signal pulse, wherein the signal receiver includes a plurality of comparators configured to sample the one or more reflected pulses at different intensity threshold levels to determine a group of slices representative of the received one or more reflected pulses, wherein each slice of at least a portion of the group of slices identifies a corresponding timing of when at least a portion of the received one or more reflected pulses met a corresponding intensity threshold level. The system further includes one or more processors configured to use the determined slices to reconstruct the one or more reflected pulses.

Abstract: A scanner for a lidar system configured to direct emitted light to scan a field of regard of the lidar system includes a mirror and an actuator assembly. The mirror includes a first end, a second end, and a reflective surface and is pivotable along a mirror axle. The actuator assembly is disposed at the first end of the mirror and includes an asymmetric motor configured to exert a torque on the mirror to cause the mirror to pivot about the mirror axle.

Abstract: To dynamically control power in a lidar system, a controller identifies a triggering event and provides a control signal to a light source in the lidar system adjusting the power of light pulses emitted by the light source. The triggering event includes identifying a particular type of object within a threshold distance of the lidar system. In some scenarios, the power is adjusted to address eye-safety concerns.

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 input optical element includes a grating coupler and a tapered optical waveguide.

Abstract: In one embodiment, a lidar system includes a light source configured to emit (i) local-oscillator light and (ii) pulses of light. Additionally, the light source is configured to impart a spectral signature of one or more different spectral signatures to each of the emitted pulses of light, where the emitted pulses of light include an emitted pulse of light having a particular spectral signature of the 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 a portion of the emitted pulse of light scattered by a target located a distance from the lidar system. The receiver includes a detector configured to produce a photocurrent signal corresponding to the local-oscillator light and the received pulse of light. The receiver also includes a pulse-detection circuit and a frequency-detection circuit.

Abstract: A receiver of a lidar system configured to receive one or more scattered light pulses from a target in a field of regard of the lidar system. The receiver includes a detector that emits an electric signal representative of the received light pulse in response to detecting the received light pulse. The receiver further includes one or more analog circuits configured to receive the electric signal from the detector, sample one or more voltages of the electric signal, and determine the energy of the received light pulse based at least on the one or more sampled voltages. The lidar system may further calculate a reflectivity and/or other characteristics of the target based at least on the energy of the received light pulse.

Abstract: An optical engine for a LiDAR system comprises an analog detection channel comprising an avalanche photodiode (APD) optically coupled to light receiving optics and bias circuitry coupled to the APD and configured to adjust a bias set point (BSP) of the APD. Sensors sense disparate environmental factors that impact optical engine performance. Memory stores pre-established APD BSP data including a nominal APD BSP and pre-established dependence data characterizing the impact of disparate environmental factors on the nominal APD BSP. A controller generates, using sensor signals, in-field dependence data characterizing the impact the disparate environmental factors currently have on the nominal APD BSP, calculate an updated APD BSP using the in-field and pre-established dependence data, and shift the BSP of the APD from the nominal APD BSP to the updated APD BSP to enhance optical engine performance.

Abstract: Implementations described and claimed herein provide a mechanically-scanning 3-dimensional light detection and ranging (3D LiDAR) system including a galvo mirror attached to an armature of a galvanometer to reflect a light signal generated by a light generator, the galvanometer comprising at least one permanent magnet, at least one coil configured to carry current to move the armature, wherein the galvo mirror is configured to reflect the light signal generated by the light generator towards a one or more objects and the galvo mirror is further configured to reflect light signal reflected from the one or more objects towards a light detector.

Abstract: An active metasurface that provides low-loss and high-bandwidth modulation control of light includes a number of cells arranged on a substrate. A controller dynamically alters a voltage differential supplied to the electrodes of each of the cells is adapted to alter refractive index of each of the high-index dielectric blocks in order to controllably steer light exiting the cell.

Abstract: A system and method are described for assessing accuracy of a virtual horizon generated by a vehicle-based lidar system as the vehicle traverses a route of travel. Travel route topology data is obtained by a vehicle vehicle-mounted global positioning system-assisted inertial measurement unit (GPS/IMU) data. A reference virtual horizon at points along the route of travel is obtained from the GPS/IMU data and is compared with the virtual horizon generated by the lidar system for the same points to assess the accuracy of the virtual horizon generated by the lidar system.

Abstract: A system for detecting boundaries of lanes on a road is presented. The system includes an imaging system configured to produce a set of pixels associated with lane markings on a road. The system also includes one or more processors configured to detect boundaries of lanes on the road, including: receive, from the imaging system, the set of pixels associated with lane markings; partition the set of pixels into a plurality of groups, each of the plurality of groups associated with one or more control points; and generate a first spline that traverses the control points of the plurality of groups, the first spline describing a boundary of a lane on the road.

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: In one embodiment, a light source is 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 the emitted optical signal. The light source also includes an optical isolator disposed between the seed laser diode and the SOA, where the optical isolator is configured to (i) transmit the seed optical signal to the SOA and (ii) reduce an amount of light that propagates from the SOA toward the seed laser diode.

Abstract: An optical receiver including an ASIC, a light detector element, and a protective mask is disclosed. The light detector element is disposed on the ASIC and has a top surface oriented toward incident light, the top surface including a portion configured to receive the incident light and via which the incident light reaches an active area of the light detector element. The protective mask is placed over the ASIC so as to (i) cover, from the incident light, a portion of the ASIC, and (ii) provide an aperture that defines an optical path for the incident light through the protective mask to the portion of the top surface of the light detector element.