In plane manipulation of a dielectric nanobeam with gradient optical forces

Abstract

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.

Classical and fluctuation‐induced electromagnetic interactions in micron‐scale systems: designer bonding, antibonding, and Casimir forces

“…Another notable approach of force enhancement can be found in exploiting symmetry in such extended periodic structures: by breaking periodicity in PhC gratings or nanobeams (e.g. by perturbing the alignment of periodic holes), ultra‐large normal and lateral forces can be engineered . The idea, first explored by Liu et al., relies on the existence of certain leaky modes, or “bright” guided modes of isolated, unstructured slabs that can couple to external radiation via the periodicity (band folding), which due to symmetry cannot couple to external radiation .…”

“…Some of these strategies are illustrated in Fig. 3 and include: adopting slow-light Bloch modes to enhance the intra-cavity optical energy [121], designing more complex morphologies to engineer the field distributions near the interacting surfaces [122,123], and incorporating metamaterials that locally engineer the dielectric profile experienced by the evanescent field in the vicinity of the nearby objects [124,125], or which effectively reduce the coupling distance perceived by the fields, thereby ameliorating the challenge of fabricating free-standing devices with thin sacrificial layers [126].…”

“…Another notable approach of force enhancement can be found in exploiting symmetry in such extended periodic structures: by breaking periodicity in PhC gratings or nanobeams (e.g. by perturbing the alignment of periodic holes), ultra-large normal and lateral forces can be engineered [104,123,130,134]. The idea, first explored by Liu et.…”