Open AccessHigh temperature fiber sensor with high sensitivity based on core diameter mismatch
Author(s) -
Linh V. Nguyen,
Dusun Hwang,
Seong Mi Moon,
Dae Seung Moon,
Youngjoo Chung
Publication year - 2008
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.011369
Subject(s) - cladding (metalworking) , multi mode optical fiber , materials science , optics , single mode optical fiber , plastic clad silica fiber , graded index fiber , fiber optic sensor , all silica fiber , optical fiber , hard clad silica optical fiber , polarization maintaining optical fiber , photonic crystal fiber , dispersion shifted fiber , plastic optical fiber , optoelectronics , wavelength , physics , composite material
We report a simple fiber sensor for measurement of high temperature with high sensitivity. The sensing head is a multimode-single mode-multimode (MM-SM-MM) fiber configuration formed by splicing a section of uncoated single mode fiber (SMF) with two short sections of multimode fibers (MMF) whose core is composed of pure silica. Because of the mode-field mismatch at the splicing points of the SMF with 2 sections of MMFs, as well as index matching between the core of the MMF and the cladding of the SMF, optical power from the lead-in fiber can be partly coupled to the cladding modes of the SMF through the MMF. The cladding modes of the SMF then re-coupled to the lead-out fiber, in the same fashion. Due to the effective index difference between the core and cladding modes, an interference pattern in the transmission spectrum of the proposed device was obtained. The interference pattern was found to shift to the longer wavelength region with respect to temperature variation. The temperature sensor can measure temperature stably up to more than 900 degrees C with sensitivity of 0.088 nm/ degrees C.