Patent ID: 11927698
Assignee: AEVA, INC.
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 7:
8. A method for increasing coherence length of a lidar system comprising:
delaying an output of a laser source utilized by the lidar system, wherein the output of the laser source includes a phase variance, and wherein the output of the laser source is delayed by an amount not greater than one half of a coherence time of the laser source;
determining a phase difference between the output of the laser source and the delayed output of the laser source;
estimating a phase error correction to correct the phase variance in the output of the laser source based on the phase difference;
modulating the output of the laser source based on the estimated phase error correction;
outputting the modulated output of the laser source as a phase corrected laser output;
determining a phase difference of a reference arm signal, the phase difference corresponding to a difference in the phase of the reference arm signal at two points in time, the reference arm signal corresponding to a portion of the phase corrected laser output;
estimating a phase correction from the phase difference, the phase correction to be applied to a target arm signal to compensate for the phase variance of the laser source, the target arm signal corresponding to a portion of the phase corrected laser output incident on and reflected back from a target;
modulating the target arm signal with the phase correction to produce a phase corrected target arm signal which compensates the target arm signal for the phase variance of the laser source; and
either delaying the reference arm signal by a delay time prior to the determining or delaying the target arm signal by the delay time prior to the modulating.