Difference Absorption Optical Fiber Methane Gas Sensor Based on FBG

摘要

In this paper, based on analysis of the near infrared spectral absorption of methane molecule and considering factors such as compatibility with the transmission characteristics of silica optical fiber and the price, using Fiber Bragg Grating (FBG) filters to replace the traditional interference filter, a novel kind of all- fiber remote sensor utilizing FBG filters and 1.33μm high power light-emitting diode (LED) was developed for real time measurement of methane gas concentration. FBG has a low insert loss and can be produced easily compared with dielectric interference filters. Theory and experiment proved that the system has simple construct and high sensibility.