Temperature-Compensated High-Sensitivity Relative Humidity Sensor Based on Band-Pass Filtering and Vernier Effect
Changgui Yu, Huaping Gong, Zhaoxu Zhang, Kai Ni, Chunliu Zhao
Abstract
Temperature-compensated high-sensitivity relative humidity (RH) sensor based on bandpass filtering and Vernier effect is proposed. The sensor with Vernier effect is formed by the cascading single-mode fiber (SMF)-hollow-core fiber (HCF)-SMF structure and coated with sensitive film at the end. While improving the RH sensitivity based on the Vernier effect, the method of bandpass filtering is used to separate the spectrum of the sensing cavity and the envelope to obtain their respective spectrum, and the problem of temperature disturbance is solved by the sensitivity coefficient matrix. Experiments show that the sensitivity of the humidity can reach 1.454 nm/% RH when the humidity rises from 35% RH to 85% RH. The stability and the response time of the sensor are also discussed.