Fig. 1. （A B）^N periodic structure of 1-D photonic crystal

Fig. 2. Dispersion curve of（A B）^N，（A B A）^N and（A B B A）^N

Fig. 3. Dispersion curve corresponding to thickness d₁，d₂ and 0.5 d₁，d₂

Fig. 4. Dispersion curve of $n_a=\mathrm{1.38}$ and $n_{\mathrm{B}}/n_{\mathrm{A}}=\mathrm{1.7}$

Fig. 5. Band gap of n_A=1.38 and $n_{\mathrm{B}}/n_{\mathrm{A}}=\mathrm{1.7}$

Fig. 6. The width of the first band gap when $n_{\mathrm{A}}$ or $n_{\mathrm{B}}/n_{\mathrm{A}}$ is a fixed value is the fixed value

Fig. 7. When $n_{\mathrm{A}}$ is a fixed value，the forbidden band width of the second forbidden band，the third forbidden band and the fourth forbidden band

Fig. 8. Forbidden band width with constant refractive index ratio

Fig. 9. Dispersion curve when coefficient，center wavelength，incident angle and refractive index ratio are the same

Fig. 10. Dispersion curve and band gap width corresponding to center wavelength 300~1 100 nm

Fig. 11. The width of the band gap of the center wavelength under different refractive index ratios

Fig. 12. The position where each band gap of the center wavelength ends under different refractive index ratios

Fig. 13. The dispersion curve and band gap width corresponding to different incident angles

Fig. 14. Dispersion curve and spectrum comparison of blue and green notch filters

Fig. 15. Dispersion curve and spectrum comparison of blue and green notch filters