Title :
Sensing Properties of Long Period Fiber Grating Coated by Silver Film
Author :
Hai-Feng Hu ; Ze-Qun Deng ; Yong Zhao ; Jin Li ; Qi Wang
Author_Institution :
Coll. of Inf. Sci. & Eng., Northeastern Univ., Shenyang, China
Abstract :
In long period fiber gratings (LPFGs), the fiber modes guided by the core layer can excite surface plasmon resonance (SPR) in the metallic thin-film coated on the cylindrical surface of fibers. In this letter, the LPFG-based fiber optic SPR sensor is analyzed numerically by unconjugated form of coupled mode method. According to the mode analysis, the EH modes can couple with surface plasmon mode and are suitable for refractive index sensing application. In wavelength interrogation, the transmission dip caused by SPR is sensitive to the environmental refractive index. The sensitivity of the sensor achieves 1660 nm/RIU in the aqueous solution.
Keywords :
coupled mode analysis; fibre optic sensors; optical films; refractive index measurement; silver; surface plasmon resonance; Ag; EH modes; LPFG; aqueous solution; coupled mode method; fiber modes; fiber optic SPR sensor; long period fiber grating; mode analysis; refractive index sensing; sensing properties; sensor sensitivity; silver film coating; surface plasmon resonance; transmission dip; wavelength interrogation; Gratings; Optical fiber sensors; Optical refraction; Optical surface waves; Plasmons; Surface plasmon resonance; coupled mode theory; long period fiber 13 grating; long period fiber grating; refractive index sensing;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2014.2361831
