Abstract: In one embodiment, a lidar system includes a light source configured to emit pulses of light and a scanner configured to scan at least a portion of the emitted pulses of light along a scan pattern contained within an adjustable field of regard. The scanner includes a first scanning mirror configured to scan the portion of the emitted pulses of light substantially parallel to a first scan axis to produce multiple scan lines of the scan pattern, where each scan line is oriented substantially parallel to the first scan axis. The scanner also includes a second scanning mirror configured to distribute the scan lines along a second scan axis that is substantially orthogonal to the first scan axis, where the scan lines are distributed within the adjustable field of regard according to an adjustable second-axis scan profile.

Abstract: To compensate for the effects of vibration on a lidar system in a vehicle, a vibration sensor within the lidar system and/or the vehicle detects vibration, such as a gyroscope, accelerometer, inertial measurement unit (IMU), etc. The detected vibration is then used to generate a compensation signal. The compensation signal is combined with a drive signal that drives a scanner configured to direct light pulses across a field of regard. The combined signal is provided to the scanner, and accordingly, the light pulses are accurately directed across the field of regard.

Abstract: To detect an atmospheric condition at the current location of a lidar system, a receiver in the lidar system detects a return light pulse scattered by a target and analyzes the characteristics of the return light pulse. The characteristics of the return light pulse include a rise time, a fall time, a duration, a peak power, an amount of energy, etc. When the rise time, fall time, and/or duration exceed respective thresholds, the lidar system detects the atmospheric condition such as fog, sleet, snow, rain, dust, smog, exhaust, or insects. In response to detecting the atmospheric condition, the lidar system adjusts the characteristics of subsequent pulses to compensate for attenuation or distortion of return light pulses due to the atmospheric condition. For example, the lidar system adjusts the peak power, pulse energy, pulse duration, inter-pulse-train spacing, number of pulses, or any other suitable characteristic.

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.

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 provided by the light pulse. Triggering events may include exceeding a threshold speed, being within a threshold distance of a person or other object, an atmospheric condition, etc. In some scenarios, the power is adjusted to address eye-safety concerns.

Abstract: To increase the effective pulse rate of a light source in a lidar system, a controller provides control signals to the light source to transmit a light pulse once the previous light pulse has been received. The controller may communicate with a receiver in the lidar system that detects received light signals. In response to detecting a received light signal, the receiver may provide an indication of the received light signal to the controller which may in turn provide a control signal to the light source to transmit the next light pulse. The receiver may also provide characteristics of the received light signal to the controller, such as the peak power for the received light signal, the average power for the received light signal, the pulse duration of the received light signal, etc. Then the controller may analyze the characteristics to determine whether to transmit another light pulse.

Abstract: In one embodiment, a lidar system includes a light source configured to emit pulses of light and a scanner configured to scan at least a portion of the emitted pulses of light across a field of regard. The lidar system also includes a receiver configured to detect at least a portion of the scanned pulses of light scattered by a target located a distance from the lidar system.

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.

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 provided by the light pulse. Triggering events may include exceeding a threshold speed, being within a threshold distance of a person or other object, an atmospheric condition, etc. In some scenarios, the power is adjusted to address eye-safety concerns.

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 provided by the light pulse. Triggering events may include exceeding a threshold speed, being within a threshold distance of a person or other object, an atmospheric condition, etc. In some scenarios, the power is adjusted to address eye-safety concerns.

Abstract: To compensate for the uneven distribution of data points around the periphery of a vehicle in a lidar system, a light source transmits light pulses at a variable pulse rate according to the orientation of the light pulses with respect to the lidar system. A controller may communicate with a scanner in the lidar system that provides the orientations of the light pulses to the controller. The controller may then provide a control signal to the light source adjusting the pulse rate based on the orientations of the light pulses. For example, the pulse rate may be slower near the front of the lidar system and faster near the periphery. In another example, the pulse rate may be faster near the front of the lidar system and slower near the periphery.

Abstract: To compensate for the effects of vibration on a lidar system in a vehicle, a vibration sensor within the lidar system and/or the vehicle detects vibration, such as a gyroscope, accelerometer, inertial measurement unit (IMU), etc. The detected vibration is then used to generate a compensation signal. The compensation signal is combined with a drive signal that drives a scanner configured to direct light pulses across a field of regard. The combined signal is provided to the scanner, and accordingly, the light pulses are accurately directed across the field of regard.

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: 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.

Abstract: To detect an atmospheric condition at the current location of a lidar system, a receiver in the lidar system detects a return light pulse scattered by a target and analyzes the characteristics of the return light pulse. The characteristics of the return light pulse include a rise time, a fall time, a duration, a peak power, an amount of energy, etc. When the rise time, fall time, and/or duration exceed respective thresholds, the lidar system detects the atmospheric condition such as fog, sleet, snow, rain, dust, smog, exhaust, or insects. In response to detecting the atmospheric condition, the lidar system adjusts the characteristics of subsequent pulses to compensate for attenuation or distortion of return light pulses due to the atmospheric condition. For example, the lidar system adjusts the peak power, pulse energy, pulse duration, inter-pulse-train spacing, number of pulses, or any other suitable characteristic.

Abstract: To increase the effective pulse rate of a light source in a lidar system, a controller provides control signals to the light source to transmit a light pulse once the previous light pulse has been received. The controller may communicate with a receiver in the lidar system that detects received light signals. In response to detecting a received light signal, the receiver may provide an indication of the received light signal to the controller which may in turn provide a control signal to the light source to transmit the next light pulse. The receiver may also provide characteristics of the received light signal to the controller, such as the peak power for the received light signal, the average power for the received light signal, the pulse duration of the received light signal, etc. Then the controller may analyze the characteristics to determine whether to transmit another light pulse.

Abstract: To compensate for motor dynamics in a scanner in a lidar system, a light source transmits light pulses at a variable pulse rate in accordance with a scan speed of the scanner. More specifically, the pulse rate may be directly related to the scan speed so that the light source transmits light pulses uniformly across a field of regard. A controller may determine the scan speed and provide a control signal to the light source adjusting the pulse rate accordingly.

Abstract: To compensate for motor dynamics in a scanner in a lidar system, a light source transmits light pulses at a variable pulse rate in accordance with a scan speed of the scanner. More specifically, the pulse rate may be directly related to the scan speed so that the light source transmits light pulses uniformly across a field of regard. A controller may determine the scan speed and provide a control signal to the light source adjusting the pulse rate accordingly.

Abstract: A lidar system with a pulsed laser diode to produce a plurality of optical seed pulses of light at one or more operating wavelengths between approximately 1400 nm and approximately 1600 nm. The lidar system may also include one or more optical amplifiers to amplify the optical seed pulses to produce a plurality of output optical pulses. Each optical amplifier may produce an amount of amplified spontaneous emission (ASE), and the output optical pulses may have characteristics comprising: a pulse repetition frequency of less than or equal to 100 MHz; a pulse duration of less than or equal to 20 nanoseconds; and a duty cycle of less than or equal to 1%. The lidar system may also include one or more optical filters to attenuate the ASE and a receiver to detect at least a portion of the output optical pulses scattered by a target located a distance.

Abstract: A lidar system with a pulsed laser diode to produce a plurality of optical seed pulses of light at one or more operating wavelengths between approximately 1400 nm and approximately 1600 nm. The lidar system may also include one or more optical amplifiers to amplify the optical seed pulses to produce a plurality of output optical pulses. Each optical amplifier may produce an amount of amplified spontaneous emission (ASE), and the output optical pulses may have characteristics comprising: a pulse repetition frequency of less than or equal to 100 MHz; a pulse duration of less than or equal to 20 nanoseconds; and a duty cycle of less than or equal to 1%. The lidar system may also include one or more optical filters to attenuate the ASE and a receiver to detect at least a portion of the output optical pulses scattered by a target located a distance.