Fig. 1. Optical constants of ultraviolet thin film materials. (a) Refractive index n; (b) extinction coefficient k

Fig. 2. Transmission spectral curves of different period numbers S

Fig. 3. Transmission spectral curve of fused silica

Fig. 4. Structure diagram of front surface film

Fig. 5. Theoretical spectral curve of front surface

Fig. 6. Structure diagram of back surface film

Fig. 7. Theoretical spectral curve of back surface

Fig. 8. Theoretical spectral curve of double-sided transmission. (a) 125-425 nm; (b) 225-235 nm

Fig. 9. Sample film craking map

Fig. 10. Degree of film craking at different deposition temperatures. (a) 200 ℃; (b) 250 ℃; (c) 300 ℃

Fig. 11. Degree of film craking at different background vacuum. (a) 4.0×10^-4 Pa; (b) 5.0×10^-4 Pa; (c) 6.0×10^-4 Pa

Fig. 12. Stress curves of thin films under different ion source parameters

Fig. 13. Degree of film craking at different ion source parameters. (a) 0 V/0 A; (b) 100 V/0.7 A; (c) 130 V/1 A; (d) 200 V/2 A

Fig. 14. Test spectral curve of front surface. (a) 200-425 nm; (b) 224-240 nm

Fig. 15. Error inversion spectral curve. (a) 200-425 nm; (b) 225-240 nm

Fig. 16. Test transmission curves of double-sided coating. (a) 115-425 nm; (b) 225-237 nm