7 µm-long all-optical 1×2 switch utilizing Si/VO2 hybrid waveguide

In this paper, a compact and CMOS compatible all-optical 1×2 switch based on directional coupler is proposed. One waveguide of directional coupler is a conventional silicon waveguide while else is a hybrid silicon/VO
₂
waveguide. By optically changing the phase of VO
₂
layer from insulating to metallic, dependent on VO
₂
thickness, a great effective refractive index modification of hybrid waveguide can be reached. The significant modifications in refractive index lead to a small length required to apply a phase shift of 3
^1/2
_π
in order to achieve switching mechanism. Our simulations result show that an extinction ratio and crosstalk of higher than 11 dB along only 7 μm length of switch is obtainable.