Design and analysis of a gas sensor based on a ring multi-wavelength fiber laser in near infrared

Numerical model of a gas sensor based on the ring multi-wavelength fiber laser is discussed to detect gas such as methane (CH4), which has multi-line absorption in near infrared. The schematic of the gas sensor is given, and its detecting principle of multiple windows is demonstrated in detail. The detecting methods based on the differential method and the second harmonic wave method in the sensor are analyzed, and the optimal information syncretions are used to process the information of the detected gas. The analyzing results show the sensor has advantages over the traditional sensor, and can be expanded to detect other gas such as acetylene (C2H4).