We report enhanced optomechanical coupling by embedding a nano-mechanical beam resonator within an optical race-track resonator. Precise control of the mechanical resonator is achieved by clamping the beam between two low-loss photonic crystal wavegu
ide couplers. The low insertion loss and the rigid mechanical support provided by the couplers yield both high mechanical and optical Q-factors for improved signal quality.
The optical binding forces between guided lightwaves in dielectric waveguides can be either repulsive or attractive. So far only attractive force has been observed. Here we experimentally demonstrate a bipolar optical force between coupled nanomechan
ical waveguides. Both attractive and repulsive optical forces are obtained. The sign of the force can be switched reversibly by tuning the relative phase of the interacting lightwaves. This tunable, bipolar interaction forms the foundation for the operation of a new class of light force devices and circuits.
