Title :
Optical Fiber Humidity Sensor With Porous TiO2/SiO2/TiO2 Coatings on Fiber Tip
Author :
Chujia Huang ; Weijing Xie ; Dongwen Lee ; Chongjie Qi ; Minghong Yang ; Min Wang ; Jianguan Tang
Author_Institution :
Nat. Eng. Lab. for Fiber Opt. Sensing Technol., Wuhan Univ. of Technol., Wuhan, China
Abstract :
A multimode optical fiber humidity sensor composed of porous oxide films is demonstrated and optimized. Relative-humidity (RH) sensing is correlated with the shift of interference fringe due to the change of effective refractive index of porous coatings when exposed to different RH environments. An optical interference model that explains the sensing principle is presented, and the fabrication process, such as vacuum degree, baking temperature, is verified. Experimental results show that the average sensitivity is 0.7 nm/%RH (3.3%RH~63%RH), the proposed sensors present high repeatability, little hysteresis, and especially highly sensitive to low and middle moisture measure.
Keywords :
fibre optic sensors; humidity sensors; hysteresis; light interference; optical fibre fabrication; optical multilayers; porous materials; refractive index; silicon compounds; titanium compounds; RH environments; TiO2-SiO2-TiO2; baking temperature; effective refractive index; fabrication process; fiber tip; hysteresis; interference fringe; low moisture measure; middle moisture measure; multimode optical fiber humidity sensor; optical interference model; porous TiO2-SiO2-TiO2 coatings; porous oxide films; relative-humidity sensing; repeatability; sensing principle; vacuum degree; Coatings; Films; Humidity; Optical fiber couplers; Optical fiber sensors; Fabry-Perot interferometer; Optical fiber sensors; Porous films; Relative-humidity; optical fiber sensors; porous films; relative-humidity;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2015.2426726
