Abstract

Development of reconfigurable photonic circuits utilizing gradient optical forces between micro- and nanoscale optical waveguides opens new possibilities for optical signal shaping and routing based on all-optical tuning of the structure geometry [1, 2]. Optomechanical interactions can be enhanced in photonic-crystal waveguides due to the increase of optical energy concentration in the slow-light regime [3] or through light trapping in cavities [4]. Whereas the pump intensity determines the strength of gradient force, the optical phase control enables tuning of interaction between side-coupled waveguides from attractive to repulsive [1, 2]. However, the independent phase control demonstrated in Refs. [1, 2] required an additional Mach-Zehnder interferometer, which increased the setup complexity. In this work, we suggest and demonstrate through 3D numerical simulations that slow-light enhanced force between side-coupled photonic-crystal waveguides can be controlled by introducing a relative longitudinal waveguide shift, which effectively defines the optical mode phase profile inside the coupler.

© 2011 IEEE