Hybrid Differential Cavity Ring-down Spectroscopic Fiber Gas Sensing Instrument sensitivity-enhanced by Thermal Lens Effect

Abstract

A new gas sensing technique based on a cavity ring down spectroscopy is proposed. This technique features the hybrid operation for enhancing the sensitivity by amplifying the optical absorption efficiency with a thermal lens (TL) effect. The limit of detection value is a few-fold higher values compared with our previous technique. It is confirmed that this hybrid operation boosted by TL effect functions with “mildly-hybrid”. Additionally, it points out that the structure of sensing head has significant function for assisting a hybrid operation.