Title :
Highly Sensitive In-Fiber Refractive Index Sensor Based on Down-Bitaper Seeded Up-Bitaper Pair
Author :
Gao, Shecheng ; Zhang, Weigang ; Geng, Pengcheng ; Xue, Xiaolin ; Zhang, Hao ; Bai, Zhiyong
Author_Institution :
Key Lab. of Opt. Inf. Sci. & Technol., Nankai Univ., Tianjin, China
Abstract :
We report a novel highly sensitive in-fiber refractive index (RI) sensor based on the Mach-Zehnder interferometer (MZI). This sensor is composed of an up-fusion-bitaper (UFBT) pair and an embedded down-stretching-bitaper (DSBT), where the UFBT excited high-order cladding modes and the DSBT enhanced the evanescent field. By employing the interaction between the strong evanescent field of high-order cladding mode and ambient environment, an RI sensitivity of 86.565 nm/cm/RIU is achieved in the RI range from 1.3332 to 1.4140. This sensitivity is about an order of magnitude higher than that of the conventional and taper-based improved in-fiber MZIs.
Keywords :
Mach-Zehnder interferometers; fibre optic sensors; optical fibre cladding; refractive index measurement; DSBT; MZI; Mach-Zehnder interferometer; RI sensitivity; RI sensor; RIU; UFBT pair; down-bitaper seeded up-bitaper pair; embedded down-stretching-bitaper; evanescent held; excited high-order cladding modes; highly sensitive in-fiber refractive index sensor; up-fusion-bitaper pair; Interference; Optical fiber sensors; Optical fibers; Refractive index; Sensitivity; Temperature measurement; Temperature sensors; Fiber taper; Mach–Zehnder interferometer; optical fiber sensor; refractive index measurement;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2012.2217949
