Open AccessOptical fiber relative humidity sensor based on FBG incorporated thin-core fiber modal interferometer
Author(s) -
Bobo Gu,
MingJie Yin,
A. Ping Zhang,
Jinwen Qian,
Sailing He
Publication year - 2011
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.004140
Subject(s) - materials science , fiber bragg grating , quartz crystal microbalance , optics , fiber optic sensor , core (optical fiber) , scanning electron microscope , optical fiber , interferometry , fiber , relative humidity , photonic crystal fiber , refractive index , optoelectronics , adsorption , composite material , chemistry , physics , organic chemistry , thermodynamics , wavelength
A new fiber-optic relative humidity (RH) sensor based on a thin-core fiber modal interferometer (TCFMI) with a fiber Bragg grating (FBG) in between is presented. Poly (N-ethyl-4-vinylpyridinium chloride) (P4VP·HCl) and poly (vinylsulfonic acid, sodium salt) (PVS) are layer-by-layer deposited on the side surface of the sensor for RH sensing. The fabrication of the sensing nanocoating is characterized by using UV-vis absorption spectroscopy, quartz crystal microbalance (QCM) and scanning electron microscopy (SEM). The incorporation of FBG in the middle of TCFMI can compensate the cross sensitivity of the sensor to temperature. The proposed sensor can detect the RH with resolution of 0.78% in a large RH range at different temperatures. A linear, fast and reversible response has been experimentally demonstrated.