Fig. 1. Schematic of slot waveguide structure

Fig. 2. Electric field distribution in the two-dimensional slot waveguide structure. (a) Overall electric field distribution; (b) electric field distribution on the line segment AB in Fig. 2(a)

Fig. 3. Effect of the four parameters on normalized energy and normalized intensity. (a) a_clad; (b) h; (c) w_slot; (d) w_slab

Fig. 4. Scanning images of normalized energy and normalized intensity during parameter optimization. (a) After h is optimized, adjust w_slot; (b) after h and w_slot are optimized, adjust w_slab; (c) after h, w_slot, and w_slab are optimized, adjust a_clad

Fig. 5. Schematic of three-dimensional slot waveguide structure

Fig. 6. Electric field distribution of three-dimensional slot waveguide structure. (a) Overall three-dimensional electric field distribution; (b) electric field distribution of xy section; (c) electric field distribution of yz section