Wavelength- and Intensity-Demodulated Dual-Wavelength Fiber Laser Sensor for Simultaneous RH and Temperature Detection

IEEE Access

Wenqi Liu¹  Bin Yin²  Guofeng Sang²  Ran Yan²  Yuheng Wu²  Qichao Wang²  Songhua Wu²  Haisu Li³  Muguang Wang³ 

[1] Chinese Academy of Sciences, Qingdao Institute of Bioenergy and Bioprocess Technology, Qingdao, China;College of Information Science and Engineering, Ocean Remote Sensing Institute, Ocean University of China, Qingdao, China;Institute of Lightwave Technology, Beijing Jiaotong University, Beijing, China;

关键词: Dual-wavelength fiber laser;    fiber laser sensor;    fiber Bragg grating;    long-period grating;    relative humidity;    temperature;   

DOI  :  10.1109/ACCESS.2020.2979470

来源: DOAJ

【 摘 要 】

We report a dual-wavelength fiber laser sensor based on a uniform fiber Bragg grating (UFBG) and a Polyvinyl alcohol (PVA) film-coated long-period grating (LPG) as sensor probe for simultaneous detection of relative humidity (RH) and temperature. Two UFBGs and the LPG were inscribed in three single mode fibers utilizing phase/amplitude mask technology and mobile scanning technique via the 248 nm UV laser. In our experiment, the RH function based on the differential intensity measurement at dual-wavelength output from 30% to 85% is in a quadratic equation, and the RH sensitivity coefficient of 0.358 dB/% shows good linear relationship and stability from 55% to 85%. Meanwhile, the temperature sensitivity coefficients based on wavelength detection and differential intensity detection are 9.1 pm/°C and 0.21 dB/°C, respectively. The structure of dual-wavelength fiber laser sensor with high signal to noise ratio (SNR), narrow spectral width and good stability enables simultaneous measurement of the RH and temperature with high accuracy and good repeatability.

【 授权许可】

Unknown