Dual-point automatic switching intracavity-absorption photonic crystal fiber gas sensor based on mode competition

Abstract

Here we propose a dual-point channel-switchable intracavity absorption hollow-core photonic crystal fiber acetylene sensing system based on the mode-competition phenomenon in a ring fiber laser with a Sagnac loop filter. The experimental system operating at 1532.83 and 1534.10nm is applied to 1% acetylene and shows the sensitivities of 398 and 1905 ppmv, respectively, at the absorption peaks around two operating wavelengths. The resolution error induced by the power fluctuation is no more than 7.2% for both gas cells and it takes ∼50s to scan the absorption spectra via applying gradient voltage to the tunable F-P filter. This approach is a potential cost-effective resolution for high-capacity intracavity absorption sensor network compatible hybrid gas detection.