DocumentCode
1505841
Title
Relative Humidity Sensor Based on Cascaded Long-Period Gratings With Hydrogel Coatings and Fourier Demodulation
Author
Yu, Xiujuan ; Childs, Paul ; Zhang, Min ; Liao, Yanbiao ; Ju, Jian ; Jin, Wei
Author_Institution
Dept. of Electron. Eng., Tsinghua Univ., Beijing, China
Volume
21
Issue
24
fYear
2009
Firstpage
1828
Lastpage
1830
Abstract
A Mach-Zehnder interferometer based on cascaded long-period gratings with a hydrogel thin-film coating is developed for monitoring the relative humidity (RH). The visibility of fringes and phase shift of the fringes are measured using Fourier analysis. The sensors show good linearity using the visibility of fringes from 60%RH to 100%RH with the ability to measure below 60% at reduced accuracy using the phase shift. An RH accuracy of 0.4% is achieved.
Keywords
Fourier analysis; Mach-Zehnder interferometers; diffraction gratings; humidity sensors; hydrogels; Fourier analysis; Fourier demodulation; Mach-Zehnder interferometer; cascaded long period grating; fringe phase shift; hydrogel thin film coating; relative humidity sensor; Cascaded long-period gratings (LPGs); hydrogel; optical fiber sensors; relative humidity (RH);
fLanguage
English
Journal_Title
Photonics Technology Letters, IEEE
Publisher
ieee
ISSN
1041-1135
Type
jour
DOI
10.1109/LPT.2009.2034620
Filename
5291749
Link To Document