Quasi-Distributed Absorption Sensing System Based on a Coherent Multiplexing Technique

A coherence multiplexing scheme for quasi-distributed absorption sensors is introduced. The sensing units are designed with different optical path lengths, and the signals from the inline sensing array can be demultiplexed by a path-scanning Michelson interferometer. Intracavity absorbance in each unit can be deduced from the corresponding signal and the signals of the previous sensing units