An Ultra-high SNR Temperature Sensor Based on PDMS-Embedded FBG Integrated Ring Laser

In this work, we proposed a high signal-to-noise ratio (SNR) temperature sensor based on a fiber ring laser cavity (FRLC). The sensor consists of a fiber Bragg grating (FBG) coated with polydimethylsiloxane (PDMS). Due to the thermal expansion effect of the PDMS material, the sensitivity of the sensor has been increased from 10 pm/°C to 12 pm/°C. Additionally, the SNR of the sensor has increased from 18 dB to 75 dB, which is attributed to the excellent monochromaticity of the laser. The designed temperature sensor system shows great application prospects in fields with significant signal loss, such as remote temperature monitoring.