Polarimetric fiber optical sensor with high sensitivity using a Fabry-Perot structure

A novel polarimetric Fabry-Perot sensor concept, based on the phase detection of the transmitted light, is presented in detail. This concept has been successfully applied to measure static force by stress induced birefringence in an optical fiber with high sensitivity. The detection scheme consists of locking the optical frequency of a laser diode to a resonance peak, where the sensitivity is highest, and using heterodyne detection to measure the phase difference between the eigenpolarizations.