In-line optofluidic refractive index sensing in a side-channel photonic crystal fiber

Nan Zhang; Georges Humbert; Zhifang Wu; Kaiwei Li; Perry Ping Shum; Nancy Meng Ying Zhang; Ying Cui; Jean-Louis Auguste; Xuan Quyen Dinh; Lei Wei

doi:10.1364/OE.24.027674

In-line optofluidic refractive index sensing in a side-channel photonic crystal fiber

Opt Express. 2016 Nov 28;24(24):27674-27682. doi: 10.1364/OE.24.027674.

Authors

Nan Zhang, Georges Humbert, Zhifang Wu, Kaiwei Li, Perry Ping Shum, Nancy Meng Ying Zhang, Ying Cui, Jean-Louis Auguste, Xuan Quyen Dinh, Lei Wei

PMID: 27906336
DOI: 10.1364/OE.24.027674

Abstract

An in-line optofluidic refractive index (RI) sensing platform is constructed by splicing a side-channel photonic crystal fiber (SC-PCF) with side-polished single mode fibers. A long-period grating (LPG) combined with an intermodal interference between LP₀₁ and LP₁₁ core modes is used for sensing the RI of the liquid in the side channel. The resonant dip shows a nonlinear wavelength shift with increasing RI over the measured range from 1.3330 to 1.3961. The RI response of this sensing platform for a low RI range of 1.3330-1.3780 is approximately linear, and exhibits a sensitivity of 1145 nm/RIU. Besides, the detection limit of our sensing scheme is improved by around one order of magnitude by introducing the intermodal interference.