Polyvinyl alcohol coated photonic crystal optical fiber sensor for humidity measurement

• Main Authors: Wong, Wei Chang, Chan, Chi Chiu, Chen, Li Han, Li, Tao, Lee, Kok Xian, Leong, Kam Chew
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Article
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Chemical engineering
• Online Access: https://hdl.handle.net/10356/97840; http://hdl.handle.net/10220/12104
• Institution: Nanyang Technological University

A polyvinyl alcohol (PVA) coated photonic crystal optical fiber (PCF) sensor has been proposed as a relative humidity (RH) sensor. It was fabricated by collapsing the holes of PCF at both ends to form a Michelson interferometer with cladding mode excitation. PVA was dip coated onto the sensor and the interference shift was measured when the sensor was exposed to varying RH. The sensor with 9% (w/w) coating showed a high sensitivity of 0.60 nm/%RH, displayed little hysteresis, high repeatability, low cross-sensitivity to temperature and ammonia gas and stability over 7 days of testing. A rise/fall time of 300/500 ms was achieved respectively.