A voltage measurement system based on fiber loop cavity ring-down technology using polymer dispersed liquid crystal film as sensing device

摘要

This paper proposed and experimentally demonstrated a high-resolution voltage measurement method based on fiber loop cavity ring-down (FLCRD) technology and polymer dispersed liquid crystal (PDLC) film as the sensing device. In this measurement system, PDLC is made into a film structure used as sensing device to measure external voltage changes, and the experiments were carried out to measure the relationships between light transmittivity of PDLC film and the external voltage. The FLCRD system with optimized structure parameters is obtained by numerical simulation, and the splitting ratios of fiber couplers used in the sensing system are optimized, and an erbium-doped fiber amplifier is used to compensate system signal loss, which has made a lot of improvement in the signal noise ratio and sensitivity. Finally, the experimental results show that the resolution of voltage measurement is 0.29 mV (0.0015%) in the range of 0-60V, which improved the resolution by 10 times compared with the current methods.