Imaging spectrometer optical design based on prism-grating-prism dispersing device

In order to make the imaging spectrometer compact and to be directly viewed, an optical system incoporating prism-grating-prism(PGP) component was designed.The system includes PGP device, collimating lens, imaging lens and receiving device. The system uses volume hologram bragg diffraction grating(VHDG) instead of ordinary ruled grating, which have high diffraction efficiency. Symmetric structure that can eliminate lateral abberations automatically is applied to this system. The requirements of design specification are given, which include 512512 pixels CCD with pixel size of 20 m20 m, 148 spectrum channels，slit size of 10 mm0.02 mm，object NA of 0.15, and operation wavelength ranging from 400 nm to 800 nm. System concept and features, diffraction efficiency, paraments relationship are discussed. According to analysis, diffraction efficiency is higher than 0.6 in the whole spectrum range. Using ZEMAX optical optimization software, the MTF of the sysytem is better than 0.7 at the Nyquist frequency, the spectural resolution is better than 3 nm, and the length of the sysytem is 90 mm.