Abstract: Optical telecommunication systems using phase-compensation interferometry wherein receiver units have N interferometer configurations each with a unique path length difference that is identical to a path length difference in one of N interferometer configurations at the corresponding transmitter units. The transmitter and receiver units separately and individually use N+1 arms, one of which serves as a reference common to the other N arms that along with the common reference arm form the N interferometer configurations of the transmitter and receiver units. N phase modulators, one in each of the N paths of the transmission units, are used to apply a separate and individual telecommunication signal (payload) to the portion of the light in that path. These N separate payloads may be of the same or different protocols. These N separate payloads may have the same or different bit rate/second. These N separate payloads may be digital or analog.

Abstract: Optical telecommunications systems use phase compensation interferometry wherein receiver units have interferometer configurations with path length differences identical to path length differences of arms in interferometer configurations at corresponding transmitter units. Faraday rotating mirrors are used to minimize sensitivity to polarization effects. A modified Michelson interferometer structure is used to provide optical signals which convert to electrical signals in a form allowing relatively easy demodulation. A demodulation circuit uses the property whereby two signals have a 90.degree. phase shift.

Abstract: Optical telecommunication systems using phase-compensation interferometry wherein receiver units have N interferometer configurations each with a unique path length difference that is identical to a path length difference in one of N interferometer configurations at the corresponding transmitter units. The transmitter and receiver units separately and individually use N+1 arms, one of which serves as a reference common to the other N arms that along with the common reference arm form the N interferometer configurations of the transmitter and receiver units. N phase modulators, one in each of the N paths of the transmission units, are used to apply a separate and individual telecommunication signal (payload) to the portion of the light in that path. These N separate payloads may be of the same or different protocols. These N separate payloads may have the same or different bit rate/second. These N separate payloads may be digital or analog.