In plane manipulation of a dielectric nanobeam with gradient optical forces

In this paper we investigate the optical forces induced by localized optical modes propagating along three parallel waveguides, of which only the central one is free to move. In this configuration, when all three waveguides are identical, the components of the optical-force acting on the free beam are decoupled along the axis of symmetry. As a result, two dimensional optomechanical control of the central waveguide, like single-mode optical trapping, can be achieved. We also study non symmetric configurations, that can be used, for example, to tailor the position of the optical trap. Unlike other techniques that rely on buckling, multi-mode excitation or radiation-pressure, single-mode optomechanical-operation should help the realization of faster and simpler on-chip positioning of a single nanobeam since most of the parameters involved can be controlled with great precision.