Long period fiber grating sensor in hollow eccentric optical fiber

Abstract

The bending characteristics of the long period fiber grating (LPFG) in hollow eccentric optical fiber (HEOF) were investigated experimentally. The results indicate that the HEOF-LPFG is insensitive to the bending and the biggest sensitivity only is 1.3nm/m^-1 in the range of 0~5m^-1. More than that, the dependences of the resonant peak on the temperature and the axial strain were also studied, obtaining the response of 56.7 pm/°С and 0.3 pm/με, respectively. Obviously, the HEOF-LPFG is more sensitive to the temperature and immune to the curvature and the strain. The HEOF-LPFG can be employed to measure the single parameter and simplify the measurement equipment in the practical application.