A differential phase shift keyed demodulator system uses a Michelson
interferometer configuration in which polarization maintenance is
accomplished by using a single 50:50 coupler coupled to a first Faraday
rotator mirror and a second Faraday rotator mirror through a first fiber
and a second fiber, respectively. In this way, system passively eliminates
the polarization problem caused by using a Mach-Zehnder interferometer.
