Time Response of a Microelectromechanical Silicon Photonic Waveguide Coupler Switch

Time response of a silicon photonic nanowire-waveguide microelectromechanical switch is studied by measuring optical output and analyzing mechanical and electrical dynamics. The switching mechanism is based on the gap variation of a directional waveguide coupler consisting of 400-nm-wide and 260-nm-thick waveguides. One of the coupler waveguides is moved by an ultrasmall comb actuator. A theoretical model is proposed by combining the mechanical motion and the electrical circuit response of the switch. By analyzing the model, an optimum condition for switching rise time is obtained to be ~10 μs, where the mechanical oscillation is suppressed by the driving electrical circuit with a large resistance. The rise time measured from the optical output intensity was 18 μs.