Fig. 1. Three-dimensional schematic diagram of designed polarization-independent metasurface optical switch. (a) Sub-unit; (b) conductive filaments formed between two sub-units; (c) metasurface array

Fig. 2. Transmission curves before and after formation of conductive filaments and normalized electric field distribution map at different wavelengths under action of TE or TM incident light. (a) (d) Variation of transmission curves before and after formation of conductive filaments; (b) (e) normalized electric field distribution map at the wavelength of 1.59 μm when conductive filament is not formed; (c) (f) normalized electric field distribution map at the wavelength of 1.55 μm when conductive filament is formed

Fig. 3. Transmission curves of metasurface under TE mode and TM mode incident lights vary with length L, width W of cross metal and thickness H of silica. (a) Variation with length L; (b) variation with width W; (c) variation with thickness H of silica

Fig. 4. Variation of extinction ratio of the metasurface optical switch with the length L, width W of the cross metal and thickness H of silica under TE mode and TM mode incident lights. (a) Variation with length L; (b) variation with width W; (c) variation with thickness H of silica

Fig. 5. Projection curves of the metasurface under the action of TE mode and TM mode incident lights vary with radius r of conductive filament and offset ∆d of conductive filament in X-axis direction. (a) Variation with conductive filament radius r; (b) variation with offset ∆d of the conductive filament in X-axis direction

Fig. 6. Variation of extinction ratio of metasurface optical switch with conductive filament radius r and conductive filament offset ∆d in X-axis direction under TE mode and TM mode incident lights. (a) Variation with conductive filament radius r; (b) variation with offset ∆d of conductive filament in X-axis direction