(under subclass 4.01) Subject matter wherein the photodetection is in response to an interference pattern formed by the interaction of coherent light waves which relate to range by a fringe pattern or fringe count.
SEE OR SEARCH THIS CLASS, SUBCLASS:
5.09, for a system that detects frequency of modulation to determine range where the beat frequency of a mixed or compared beam is not directly related to a coherent interference fringe count.
5.11, for phase change counting between known frequencies of modulation that are unrelated to coherent carrier mixing in the production of fringes.
5.15, for a system that demodulates a return beam by coherent or incoherent mixing in order to shift the return to a different IF operating frequency unrelated to counting of fringes.
28.5, for a system where frequency is detected from the mixing of coherent waves that produce a moving, interference pattern or just a difference frequency, which is related to velocity.
