Optical Gas Sensor Based on Gas Conjugated Interference Light Source

A high-speed gas-specific approach for gas detection is proposed and experimentally demonstrated. It is based on a conjugated interferometer which transforms the absorption spectrum of the sample gas to a conjugated emission spectrum. By combining such conjugated interferometer with broadband optical gain medium, a comb light source which emits light at gas absorption lines is produced. The absorption of the conjugated interference source is very weak for other types of gases whose absorption lines are typically different, but is relatively strong for the same type of gas used in the conjugated interferometer. A high sensitivity, high speed, and high specificity gas sensor is produced with the conjugated interference source.