月球与深空探测技术研究室知识库

In order to overcome the problems of low diffraction efficiency, large aberrations and stray light of traditional ruled gratings in reflective Raman spectrometers, combined with the characteristics of the Raman signals of lunar surface minerals, a volume phase holographic (VPH) grating Raman spectrometer system for lunar surface detection was designed. The spectral range of the spectrometer is 140∼3073cm-1, and the field of view is 3°. According to the Kogelnik coupled wave theory, the diffractive efficiency of the designed VPH grating is more than 95% at the central wavelength, and the average efficiency is more than 80% in the whole spectral range. After optimizing with zemax, the MTF of the entire spectrometer system at the Nyquist frequency is greater than 0.45, and a spectral resolution of 10 cm-1 can be achieved. Copyright © 2021 SPIE.