Fig. 1. F-P film structure diagram

Fig. 2. Optical constant curves of two materials. (a) SiO₂; (b) Ta₂O₅

Fig. 3. Design curve of the film system

Fig. 4. Structure diagram of optical film thickness monitoring system

Fig. 5. SiO₂ film monitoring curve

Fig. 6. Surface roughness changes before and after coating at different rates. (a) Ta₂O₅; (b) SiO₂

Fig. 7. Variations of film surface roughness under different ion source energies. (a) Ta₂O₅; (b) SiO₂

Fig. 8. Test spectral curve of the filter film

Fig. 9. Spectral curve of 44-layer dual-chamber membrane system

Fig. 10. Influence of thickness change of Ta₂O₅ on spectral curve of the film system. (a) Relative thikness of Ta₂O5 is 0.9; (b) relative thickness of Ta₂O₅ is 0.95; (c) relative thickness of Ta₂O₅ is 1.05; (d) relative thickness of Ta₂O₅ is 1.1

Fig. 11. Influence of SiO₂ thickness change on spectral curve of the film system. (a) Relative thickness of SiO₂ is 0.9; (b) relative thickness of SiO₂ is 0.95; (c) relative thickness of SiO₂ is 1.05; (d) relative thickness of SiO₂ is 1.1

Fig. 12. Debugging flow chart

Fig. 13. Relative sensitivity of each film layer in the film system

Fig. 14. Spectral curve after improvement