Passive stabilization scheme for polarization mode interferometers using a polarization beam splitter

A passive stabilization scheme for polarization mode interferometers (PMIs) using a polarization beam splitter (PBS) is proposed and experimentally demonstrated. Polarization eigenmodes in a highly birefringent fiber are modulated by external signals. Quadrature signals utilized in demodulation algorithm are acquired from the square roots of the photo-voltages, which are detected from the transmission lights of the PBS. Experimental results show that the scheme has a large dynamic range (100.8 dB), good linearity (99.937%) and is capable of high sensitivity (10−7 rad detectability above 150 Hz). Furthermore, it is immune to intensity noise of lasers so that the system instability and complexity are obviously reduced.