Recently, Gao Xiaoming, a research team of the Anguang Institute of Hefei Research Institute of the Chinese Academy of Sciences, made new progress in laser heterodyne spectral detection technology. The relevant research results were published in the academic journal Optics Express of the American Optical Society (OSA) under the title of "Research on Dual channel Mid infrared Laser Heterodyne Radiometer Based on MEMS Modulators, and Remote Sensing Monitoring of Methane CH4, Water H2O and Nitrous Oxide N2O in the Atmosphere".
In the mid infrared band, due to the lack of mature optical fiber components or optical waveguides, traditional mechanical choppers are usually used to achieve sunlight modulation, which makes it difficult to miniaturize the system. The team's associate researcher Tan Tu and doctoral student Xue Zhengyue designed a dual channel mid infrared laser heterodyne spectrometer based on a MEMS modulator. MEMS galvanometers were used to replace traditional mechanical choppers. At the same time, two inter band cascaded lasers (ICLs) located at 3.53 μ m and 3.93 μ m of methane CH4, water H2O and nitrous oxide N2O absorption lines and solar beat were measured experimentally, The volume mixing ratio of methane CH4, water H2O and nitrous oxide N2O is ～ 1.906ppm, ～ 3069ppm and ～ 338ppb respectively through inversion calculation. The dual channel MIR-LHR based on MEMS modulator reported in this report has an important application prospect, which lays a foundation for further development of portable high spectral resolution laser heterodyne spectrometer for remote sensing detection of atmospheric multi-component gases.
This research work was supported by the key programs of the National Natural Science Foundation of China and the national key research and development plan.
Source: Hefei Research Institute, Chinese Academy of Sciences
