An optical fiber voltage sensor based on self-mixing interference

An optical voltage sensor based on self-mixing interference (SMI) and on the converse piezoelectric effect of a piezoelectric ceramic (PZT) is proposed and demonstrated. A single-mode fiber is coiled around the PZT, and when an AC voltage is applied, the deformation of the PZT modulates the phase of the light propagation in the fiber. Light reflected at the fiber end back into the laser cavity forms SMI, and the voltage is obtained by demodulating the output signal with the reverse point recognition algorithm. Experimental results show that the sensor has good linearity, and the scheme has a relative error of & PLUSMN;2 %, which meets the standard IEC 60044-7.