Fig. 1. (a) 3D and (b) lateral view of the proposed optical switch inserted with an HMM structure consisting of 20-pair alternating VO2/Si layers on a glass substrate.

Fig. 2. (a) Transmittance diagram of TON based on dielectric VO2 layers with varying k of n˜exp(D). (b) Using the same dielectric VO2 layers with constant n˜exp(D)=3.1309+0.3612i, relationship curve of MD-dm is calculated based on metallic VO2 layers for different k of n˜exp(M).

Fig. 3. Electric field distribution of TE mode propagation for (a) “ON” and (b) “OFF” state with zoom-in views of the HMM structure.

Fig. 4. Power flux density Poavx distribution of TE mode propagation for (a) “ON” and (b) “OFF” state with zoom-in views of the HMM structure.

Fig. 5. Transmission diagram of (a) TON (D) and (b) TOFF (M) for an optical switch with dm varying from 5 to 55 nm.

Fig. 6. Electric field intensity distribution in an optical switch in“OFF” state with different HMM length of (a) LHMM=200  nm (dm=dd=5 nm) and (b) LHMM=600  nm (dm=dd=15 nm).

Fig. 7. Calculated (a) MD and (b) IL as a function of wavelength with dm (LHMM) varying from 5 nm (200 nm) to 55 nm (2200 nm).

Fig. 8. Based on an optical switch using W-doped VO2 layers (dm=5  nm), MD varies as a function of both n and k of n˜exp(M).