Techniques for multiplexing optical beams in coherent LiDAR systems

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

• a first beam splitter to multiplex a first optical beam and a second optical beam into a combined beam having orthogonal linear polarizations;
• a local oscillator that splits a portion of the combined beam to generate a multiplexed local oscillator signal having orthogonal linear polarizations;
• an optical arrangement comprising lensing optics configured to emit the combined beam towards a target and collect light returned from the target in a return optical beam, wherein the first beam splitter demultiplexes the return optical beam and the multiplexed local oscillator signal into a first return beam combined with a first local oscillator signal and a second return beam combined with a second local oscillator signal, and wherein the first return beam and the first local oscillator signal generate a first beat frequency and the second return beam and the second local oscillator signal generate a second beat frequency;
• and
• a signal processing system to determine a range and velocity of the target from the first beat frequency and the second beat frequency.