Abstract
This paper presents the optical design of a high-resolution double-grating spectrometer for extracting the multiple lines in the Stokes or anti-Stokes branch of the pure rotational Raman spectra of nitrogen. The spectrometer is composed of collimating and focusing mirrors, two reflective gratings, and a linear detector. The structural parameters were calculated using geometric configuration, dispersion, and aberrational theory, and conditions for first-order correction of keystone distortion with divergent grating illumination were derived. Based on this method, we simulated a spectrometer with a 16-channel linear array photomultiplier tube, resulting in uniformly distributed single-branch lines on each detector channel. The resolution reached 0.225 nm per channel, and the keystone distortion was less than 0.7%. The spectrometer avoids the interference of elastic signals by not detecting them, enabling the extraction of atmospheric temperature profiles via separated single-branch lines with high precision. Our design provides a promising solution to extract atmospheric temperature profiles for pure rotational Raman lidar.
© 2023 Optica Publishing Group
Full Article | PDF ArticleMore Like This
Chen Wang, He Chen, Yinchao Zhang, Siying Chen, Pan Guo, and Lifu Wang
Appl. Opt. 58(28) 7789-7794 (2019)
Jingyu Jia and Fan Yi
Appl. Opt. 53(24) 5330-5343 (2014)
Fuchao Liu and Fan Yi
Opt. Express 22(23) 27833-27844 (2014)