Angung Institute has made further progress in the research of high resolution la

Recently, the research team of Gao Xiaoming of angung Institute of Hefei Research Institute of Chinese Academy of Sciences has made new progress in laser heterodyne spectrum detection technology. The relevant research results were published in Optics Express, an academic journal of the Optical Society of America (OSA), with the title of "Research on Remote Sensing Monitoring of methane CH4, water H2O and nitrous oxide N2O in the atmosphere with a dual channel mid infrared laser heterodyne radiometer based on MEMS modulator".

In the mid infrared band, due to the lack of mature optical fiber components or optical waveguides, the traditional mechanical chopper is usually used to realize the sunlight modulation, and the system is difficult to achieve miniaturization. Associate researcher Tan Tu and Dr. Xue Zhengyue of the team designed a set of dual channel mid infrared laser heterodyne spectrometer based on MEMS modulator. The MEMS galvanometer is used to replace the traditional mechanical chopper.

At the same time, two inter band cascade lasers (ICLs) located at the absorption lines of methane CH4, water H2O and nitrous oxide N2O (3.53 μ m and 3.93 μ m) are beat with sunlight. The laser heterodyne spectra of the two channels (Hefei, China) are measured experimentally. The volume mixing ratios of methane CH4, water H2O and nitrous oxide N2O are ∼ 1.906ppm, ∼ 3069ppm and ∼ 338ppb, respectively. The dual channel mir-lhr based on MEMS modulator reported in this report has great application prospects, which lays a foundation for further research and development of portable high spectral resolution laser heterodyne spectrometer for remote sensing detection of atmospheric multicomponent gases.

This research was supported by the key projects of the National Natural Science Foundation of China and the national key research and development program.

Paper link：https://opg.optica.org/oe/fulltext.cfm?uri=oe-30-18-31828&id=492583

Schematic diagram of dual channel mid infrared laser heterodyne radiometer

Vertical concentration distribution map of inversion calculation

Source: Hefei Institute of materials