Aeva, Inc.

A light detection and ranging (LIDAR) technique that includes generating a baseband signal based on an optical beam and processing the baseband signal to identify beat frequencies corresponding with the plurality of up-chirps and down-chirps. The technique also includes identifying, in the baseband signal, a single-frequency detection comprising a detected beat frequency that lacks a complimentary beat frequency. The technique also includes computing an estimated range and an estimated velocity of a point based on the single-frequency detection and adding the point to a point cloud.

Aspects of the present disclosure provide light detection and ranging (LIDAR) systems and methods for using an electro-optical phase-locked loop (EOPLL) and algorithmic frequency locking hybrid driver to lock a beat frequency to the reference frequency. By using the hybrid driver, the present disclosure solves an architectural problem of LIDAR systems related to limited (e.g., narrow and applicable) reference frequency ranges, and provides a flexible and broad reference frequency range coverage. The present disclosure thus allows LIDAR systems to use the hybrid laser driver to effectively change hardware configurations to achieve desired reference frequencies.

A light detection and ranging (LIDAR) system determines a likelihood metric for a spectrum of frequencies of a frequency domain waveform. The LIDAR system modifies the likelihood metric for the spectrum of frequencies based on a parameter associated with the frequency domain waveform and a weight to generate a modified likelihood metric for the spectrum of frequencies. The LIDAR system selects a peak frequency from the spectrum of frequencies corresponding to a frequency with a highest value for the modified likelihood metric. The LIDAR system determines a property of a target based on the selected peak frequency.

A method of adjusting a detection threshold in a frequency-modulated continuous wave (FMCW) light detection and ranging (LIDAR) system includes determining a first confidence threshold with respect to a confidence metric for detecting a first target within a range of frequencies corresponding to a field of view of the LIDAR system, determining a subset of frequencies within the range of frequencies for detecting a second target, wherein a frequency peak associated with the second target has a confidence metric value lower than the first confidence threshold, and adjusting the first confidence threshold to a second confidence threshold at the subset of frequencies for detecting the second target.

The system includes an optical element to receive, responsive to transmitting the optical beam, a first returned reflection having a first lag angle relative to the optical axis. The optical element is to steer, based on the first lag angle, the first returned reflection to generate a first steered beam that is separated from the optical axis by a first offset. The system includes a multi-tip coupler that includes multiple tips. The multi-tip coupler is to receive, from the optical element, a peak power of the first steered beam at an input of a first tip of the multi-tip coupler. The input of the first tip is separated from the optical axis by the first offset. The multi-tip coupler is to combine energy from the multiple tips of the multiple-tip coupler to generate a first single mode signal to be used for detecting a position of the first object.

A method of aligning an optical lens in a LiDAR system includes emitting an optical beam by an optical source. The method includes placing the optical lens in front of a photodetector at a first predetermined position. The method further includes moving the optical lens to a plurality of Z-positions along a direction of an optical axis, the plurality of Z-positions corresponding to a plurality of parameter values of the LO signal. The method further includes generating a fitting function based on a set of values of the LO signal; and determining a parameter value of the LO signal for each Z-position. The method includes determining an initial Z-axis position of the optical lens by selecting a Z-position from the plurality of Z-positions based on a plurality of parameter values. The method includes determining a final Z-position of the optical lens by adding an offset to the initial Z-axis position.

The FMCW LiDAR system includes an optical drive electronic circuit to receive a reference frequency signal and a beat frequency signal to generate a drive signal. The optical drive electronic circuit includes a TDC to calculate a phase difference between the reference frequency signal and the beat frequency signal and a digital ramp control to: provided the phase difference is a positive value, produce a ramp down control signal to increase a current chirp rate to an increased chirp rate; provided the phase difference is a negative value, produce a ramp up control signal to decrease the current chirp rate to a decreased chirp rate. The optical drive electronic circuit includes a digital integrator to generate a digital output based on at least one of the ramp down control signal or the ramp up control signal and a DAC to convert the digital output to an analog output.

A light detection and ranging (LIDAR) system includes a beam collimator, a plurality of first lenses, a plurality of tunable lenses, and one or more optical sources to generate a plurality of optical beams. Each tunable lens may be disposed adjacent a respective one of the plurality of first lenses such that the respective one of the plurality of first lenses is between the tunable lens and the beam collimator. Each of the plurality of optical beams may pass through one of the tunable lenses and one of the first lenses towards the beam collimator. Each of the plurality of tunable lenses may be separately controllable by selectively applying voltage to the tunable lens to adjust a focal length of the tunable lens to compensate for a variation in focus positions of the plurality of first lenses.

A light detection and ranging (LIDAR) system includes a plurality of optical sources to generate a plurality of optical beams and at least one optical component adjustable to shift the plurality of optical beams to align with a reference output beam pattern prior to propagating to output scanning optics.

Aspects of the present disclosure provide an amplifier chip comprising: an optical source configured to generate a plurality of beams, a plurality of output waveguides configured to convey the plurality of beams, a plurality of semiconductor optical amplifiers (SOAs), each of the plurality of SOAs configured to receive a respective beam from the plurality of waveguides and amplify the respective beam, and a plurality of output couplers configured to output the plurality of amplified beams from the amplifier chip. The apparatus further comprises a silicon photonic integrated circuit (SPIC), comprising: a plurality of input couplers, where each of the plurality of input couplers is aligned with a respective output coupler on the amplifier chip so as to receive the plurality of amplified beams, and optical processing circuitry disposed on the SPIC and configured to receive and process one or more of the amplified beams from the plurality of input couplers.