Dynamic response of silicon photonic variable-gap waveguide coupler switch

Dynamic response of a silicon photonic nanowire-waveguide microelectromechanical switch is studied theoretically and experimentally. The switching mechanism is based on gap-variation of a directional waveguide coupler consisting of 400-nm-wide and 260-nm-thick waveguides. Analyzing an electrical and mechanical model, an optimum switching rise-time is estimated to be around 10 μsec. The rise-time measured from the optical output intensity was 18 μsec under a condition of slightly overdumping.