Fig. 1. Schematics of the unit structure of UV broadband absorber. (a) Three-dimensional view; (b) top view

Fig. 2. Dielectric constant of TiN versus wavelength

Fig. 3. Contour plot depicting the structure transmittance as a function of substrate thicknesses t1 and wavelength

Fig. 4. FNN model

Fig. 5. Loss value varies with the number of epochs when training FNN

Fig. 6. Comparison of absorption spectra simulated and predicted by trained FNN

Fig. 7. TNN model

Fig. 8. Loss value varies with the number of epochs when training TNN

Fig. 9. Comparison of absorption spectra simulated and predicted by trained TNN

Fig. 10. Comparison of target absorption spectrum, TNN predicted absorption spectrum, and simulated absorption spectrum at incident angle of 50°

Fig. 11. Contour plots of absorptivity. (a) TM wave incidence; (b) TE wave incidence

Fig. 12. Absorption spectra of TM and TE waves at incident angle of 0°

Fig. 13. Contour plots of absorptivity corresponding to different azimuth angles at incident angle of 0°

Fig. 14. Relative impedance versus wavelength

Fig. 15. Electromagnetic field distributions at 290 nm when TM wave and TE wave are vertically incident. (a)‒(c) Electric field distribution of TM wave; (d)‒(f) magnetic field distribution of TM wave; (g)‒(i) electric field distribution of TE wave; (j)‒(l) magnetic field distribution of TE wave