A DFB-FL Wavelength Shift Interrogating Scheme Based on C2H2 Absorption Spectrum

A Distributed feedback fiber laser (DFB-FL) wavelength shift interrogation scheme based on C
₂
H
₂
absorption spectrum is demonstrated in this paper, the interrogation scheme takes advantage of the transformation the wavelength shift to intensity change of the light by gas absorption spectrum. Interrogation the wavelength shifting of the DFB-FL by C
₂
H
₂
absorption line around 1535nm is taken as example. The theory, structure of the systems, resolution analysis is presented in detail. Because gas absorption spectrum is stable, the system based on this interrogation scheme has high precision and stability; it has good prospects in DFB-FL sensor wavelength interrogation system.