An optical switch is described that includes two optical waveguides, which are defined in a semiconductor layer, positioned proximate to an intermediate component, such as a micro-resonator or a directional coupler. Material underneath a portion of either or both optical waveguides is removed so that the portion of either or both optical waveguides is free standing, and a group of electrodes is proximate to the free-standing portion of either or both optical waveguides. During operation of the optical switch, a spacing-control circuit applies an electrical signal to the group of electrodes. An electrostatic force associated with the electrical signal modifies a spacing between the free-standing portion of either or both optical waveguides and the intermediate component, thereby substantially increasing optical coupling between either or both optical waveguides and the intermediate component to convey a broadband optical signal between the optical waveguides.