Self-collimation in 3D photonic crystals

Abstract

Abstract In this paper we present self-collimation in three-dimensional (3D) photonic crystals (PhCs) consisting of a simple cubic structure. By exploiting the dispersive properties of photonic crystals, a cubic- like shape equi-frequency surface (EFS) is obtained. Such surfaces allow fo r structureless confinement of light. Due to the degeneracy of propagation modes in a 3D structure, self-collimation modes can be distinguished from other modes by launching a source with a particular polarization. To this end, we found that polarization dependence is a key issue in 3D self-collimation. The results hold promise for high-density PhCs devices due to the lack of structural interaction. Finally, a novel method for the fabrication of three-dimensional (3D) simple cubic photonic crystal structures using conventional planar silicon micromachining technology is presented. The method utilizes a single planar etch mask coupled with time multiplexed sidewall passivation and deep anisotropic reactive ion etching in combination with isotropic etch processes to create three-dimensional photonic crystal devices. In itial experimental results are presented.