Study on optical fiber CO gas sensor based on difference absorption

Abstract

By analysing the near infrared spectral absorption of CO molecule and considering factors such as compatibility with the transmission characteristics of silica optical fiber and the price, a kind of all- fiber remote sensor utilizing Fiber Bragg Grating(FBG) filters and 1.567μm high power light-emitting diode (LED) was developed for real time absorption measurement. And a novel faint signal detective method by using a digital phase sensitive detector (DPSD) is designed. 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. © 2006 IOP Publishing Ltd.