Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2015-04-01

Journal: OPTICS COMMUNICATIONS

Included Journals: Scopus、EI、SCIE

Volume: 340

Page Number: 50-55

ISSN: 0030-4018

Key Words: Optical fiber sensor; Multimode interference (MMI); Refractive index sensing; Core less silica fiber; End-reflection structure

Abstract: A reflective fiber-optic refractive index (RI) sensor based on multimode interference (MMI) is presented and investigated in this paper. The sensor is made by splicing a small section of coreless silica fiber (CSF) to the standard single mode fiber (SMF). A wide-angle beam propagation method (WA-BPM) is employed for numerical simulation and design of the proposed RI sensor. Based on the simulation results, a RI sensor with a length of 1.7 cm of CSF is fabricated and experimentally studied. Experimental results show that the characteristic wavelength shift has an approximately linear relationship with the RI of the sample. A sensitivity of 141 nm/RIU (refractive index unit) and a resolution of 2.8 x 10(-5) are obtained in the RI range from 1.33 to 138. As the RI value is higher than 1.38, the sensitivity of the sensor increase rapidly as the RI increase and a maximum sensitivity of 1561 nm/RIU can be achieved, corresponding to a resolution of 2.6 x 10(-6). The experimental results fit well with the numerical simulation results. (C) 2014 Elsevier B.V. All rights reserved.