Fig. 1. Schematic diagram of reconfigurable PBS (inset: cross-sectional view of the coupling region and the end of the output waveguide)

Fig. 2. Electric field distributions of the dominant part component for five supermodes in the coupler at 1550 nm wavelength. (a)‒(c) 1st symmetric, 2nd symmetric, and antisymmetric TM supermodes, respectively; (d) (e) even and odd TE supermodes, respectively

Fig. 3. Experimental results. (a) Variations of the geometric parameters of GSST satisfying the phase-matching condition; (b) coupling length for the TM mode L_TM and the ratio of the coupling length between two modes L_TE/L_TM as functions of the width of GSST w_G

Fig. 4. Effect of the coupling length of the device L_c on the performance of PBS. (a) TE mode; (b) TM mode

Fig. 5. Simulated propagation of the electric field at the wavelength of 1550 nm. (a) TE mode (amorphous); (b) TE mode (crystalline); (c) TM mode (amorphous); (d) TM mode (crystalline)

Fig. 6. Performance of the device at the wavelength from 1500 nm to 1600 nm. (a) Amorphous; (b) crystalline

Fig. 7. Variations of ER and IL within process tolerance range for TE and TM modes. (a) Width of input or output waveguide δw₁; (b) width of intermediate waveguide δw₂; (c) gap between the waveguides δG