Polarimetric current sensor based on polarization division multiplexing detection.

A polarimetric current sensor based on polarization division multiplexing (PDM) detection is proposed. The novel sensor head with a heat insulation cavity only induces a small level of birefringence. Comparing with polarization diversity (PD) detection, the sensitivity of PDM detection is the double of PD detection. Moreover, PDM detection is more suitable in the presence of the phase modulation error. In addition, the noise and the shifting of the Verdet constant are proved to be the main influence factors of the sensor performance as the source power decline.