OPTICAL DELAY LINE TO CORRECT PHASE ERRORS IN COHERENT LADAR

摘要

A ladar system (40) with phase correction. The novel ladar system (40) includes optics (52) for receiving a first signal (56) that is a reflected version of a transmitted laser signal (46), an optical delay line (60) for providing a second signal (62) that is a delayed version of the transmitted laser signal (46), and a mechanism (58) for mixing the first signal (56) with the second signal (62). The second signal (62) is delayed by a time TD that reduces a relative time difference between the first and second signals such that phase errors caused by laser transmitter instabilities and nonlinear modulation are less than a predetermined level.