Nonlinear Dielectric Optomechanical Metamaterials

Abstract: We introduce a dielectric photonic metamaterial presenting a giant nonlinear optical response driven by resonant optomechanical forces. It exhibits optical bistability and nonlinear asymmetric transmission at intensity levels of only a few hundred µW/µm 2 Optical forces are extremely important in mesoscopic systems: they are exploited in all forms of optical tweezing, manipulation and binding, as well as for actuation of nanophotonic devices [1]. Here we introduce the concept of optomechanical metamaterials – a new type of dielectric metamaterial that provides strongly nonlinear and asymmetric optical properties via the mutual interaction of optical and mechanical responses to low intensity illumination. Metamaterials provide a unique platform for manipulating electromagnetic fields, and thereby optical forces, on the nanoscale [2]. The optomechanical metamaterial considered here comprises an array of dielectric meta-molecules supported on free-standing elastic beams (Fig.1a). The metamaterial supports a Fano-type optical resonance in the vicinity of which strong, illumination-direction-dependent optical forces are generated within and among the dielectric meta-molecule cells (Fig.1b). Numerical analyses reveal that these optomechanical forces provide a strong nonlinear optical response mechanism delivering optical bistability at intensity levels of only a few hundred µW/µm