Holographic Design and Fabrication of Diamond Symmetry Photonic Crystals Via Dual-Beam Quadruple Exposure

摘要

Three-dimensional (3D) photonic crystals (PCs) with complete photonic bandgaps (PBGs) are of interest in optical integrated circuits for applications, including localizing, manipulating, and guiding light omnidirectionally. So far, calculation shows that the diamond symmetry structure, belonging to space group Fd3m (No. 227), offers the largest complete PBG (2-3 gap). To fabricate PCs with a unit cell size at the (sub)micrometer scale, various techniques have been investigated, including microman-ipulation, layer-by-layer lithography, direct laser writing, and direct-write assembly. Nevertheless, they are typically laborious, therefore, fabrication is often limited to a few unit cells.