Optical Fiber Fabry-Perot Humidity Sensor Based on BPQDs-PVA Sandwiched in SMF

An optical fiber humidity sensor based on filmy black phosphorus quantum dots- polyvinyl alcohol (BPQDs-PVA) gel sandwiched between two sections of single-mode fibers (SMFs) is proposed. The BPQDs-PVA compound serves as Fabry-Perot (FP) cavity that directly perceives external humidity variations and modulates the reflection spectrum. Based on the excellent hygroscopicity of BPQDs-PVA compound, the humidity sensor achieved a humidity sensitivity of 0.2259 nm/%RH in the range of 42-57 %RH, and an ultra-high humidity sensitivity of 12.4307 nm/%RH in the range of 57-60 %RH. The maximum instability of the sensor is 0.02 %RH, and the response/recovery time are 0.78s/1.24s, respectively. Easy fabrication process, low cost, good stability and high sensitivity make it has great potential in fields which need accurate humidity monitor and control.

Automated summary

An optical fiber humidity sensor based on BPQDs-PVA gel has been proposed, which shows great potential in accurately monitoring and controlling humidity due to its easy fabrication, low cost, good stability, and high sensitivity.