Fig. 1. Schematic of AOTF

Fig. 2. Main interface of echelle grating

Fig. 3. Structure of the telescopic imaging system. (a) Two-dimensional view; (b) three-dimensional view

Fig. 4. MTF curves of telescopic system of each band. (a) 2320 nm; (b) 3285 nm; (c) 4250 nm

Fig. 5. RMS point diagrams of telescopic system of each band. (a) 2320 nm; (b) 3285 nm; (c) 4250 nm

Fig. 6. Structure of echelle spectrograph

Fig. 7. MTF curves of echelle spectrograph of each band. (a) 2320 nm; (b) 3285 nm; (c) 4250 nm

Fig. 8. RMS point diagrams of echelle spectrograph of each band. (a) 2320 nm; (b) 3285 nm; (c) 4250 nm

Fig. 9. Overall structure of imaging spectrometer

Fig. 10. MTF curves of overall structure of each band. (a) 2320 nm; (b) 3285 nm; (c) 4250 nm

Fig. 11. RMS point diagrams of overall structure of each band. (a) 2320 nm; (b) 3285 nm; (c) 4250 nm