Numerical and Experimental Analysis of Sensitivity-Enhanced RI Sensor Based on Ex-TFG in Thin Cladding Fiber

Author

Zhijun Yan ; Zhongyuan Sun ; Kaiming Zhou ; Binbin Luo ; Jianfeng Li ; Hushan Wang ; Yishan Wang ; Wei Zhao ; Lin Zhang

Author_Institution

Aston Inst. of Photonic Technol., Aston Univ., Birmingham, UK

Volume

33

Issue

14

fYear

2015

Firstpage

3023

Lastpage

3027

Abstract

We report a highly sensitive refractive index (RI) sensor in the aqueous solution, which is based on an 81°-tilted fiber grating structure inscribed into a thin cladding fiber with 40 μm cladding radius. The numerical analysis has indicated that the RI sensitivity of cladding resonance mode of the grating can be significantly enhanced with reducing cladding size. This has been proved by the experimental results as the RI sensitivities of TM and TE resonance peaks in the index region of 1.345 have been increased to 1180 nm/RIU and 1150 nm/RIU, respectively, from only 200 and 170 nm/RIU for the same grating structure inscribed in standard telecom fiber with 62.5-μm cladding radius. Although the temperature sensitivity has also increased, the change in temperature sensitivity is still insignificant in comparison with RI sensitivity enhancement.

Keywords

diffraction gratings; fibre optic sensors; optical fibre cladding; refractive index measurement; 81°-tilted fiber grating structure; Ex-TFG; RI sensitivity enhancement; TE resonance peak; TM resonance peak; aqueous solution; cladding radius; cladding resonance mode; cladding size; numerical analysis; radius 40 mum; radius 62.5 mum; refractive index sensor; sensitivity-enhanced RI sensor; standard telecom fiber; temperature sensitivity; thin cladding fiber; wavelength 1150 nm; wavelength 1180 nm; Fiber gratings; Gratings; Optical fiber dispersion; Optical fiber polarization; Optical fiber sensors; Sensitivity; Refractive index (RI) sensing; Refractive index sensing; Sensitivity; Tilted fiber grating; sensitivity; tilted fiber grating (TFG);

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2015.2422076

Filename

7089159