Fig. 1. Schematic diagram of thin film interference

Fig. 2. Schematic diagram of spectral imaging system

Fig. 3. Transmission spectrum curves at different incidence angles

Fig. 4. Relation between central wavelength and angle of incidence of narrow band filter

Fig. 5. Optimized imaging system

Fig. 6. Image quality evaluation of optical system

Fig. 7. Schematic diagram of composition of spectral image acquisition system

Fig. 8. Spectral image acquisition system

Fig. 9. Spectral images at different incidence angles