Techniques for descan compensation in a FMCW LiDAR system

A light detection and ranging (LiDAR) system, comprising:

• an optical subsystem with an optical axis, comprising:
• an optical source to emit an optical beam;
• a first optical lens to transmit the optical beam;
• an optical window aligned with the first optical lens to reflect a first portion of the optical beam to generate a local oscillator (LO) signal;
• an optical scanner to transmit a second portion of the optical beam to a target to scan the target to generate a target return signal;
• a second optical lens to transmit the LO signal and the target return signal to a photodetector (PD),
• the photodetector (PD) to mix the target return signal with the LO signal to extract range and velocity information of the target, wherein the LO signal is disposed to be decentered from the optical axis on the second optical lens to increase a percentage of an overlap of the LO signal and the target return signal on a detection plane of the PD.