US Patent 10295673 Nested interferometer for optical autocovariance lidar

Lidar systems and methods are provided. The lidar system includes a laser that outputs light at two different wavelengths and an interferometer that is capable of generating fringe patterns for each of the two wavelengths simultaneously. More particularly, a first arm of the interferometer provides first and second path lengths. Light of a first of two or more wavelengths traverses the first path length within the first arm, while light of a second one of the two wavelengths traverses the second path length within the first arm. A second arm of the interferometer provides a third path length. Light from the first and second arms is then combined, and a phase shift of light of the first wavelength and a phase shift of light of the second wavelength are determined.