Waveguide networks in three-dimensional layer-by-layer photonic crystals

Different types of waveguides and connections between them were fabricated in a three-dimensional (3D) layer-by-layer photonic crystal. The waveguides were formed by removing either a single rod or a series of rod fragments running in three mutually orthogonal directions. This provides the potential of forming a 3D network of waveguide channels with cross sectional dimensions on the order of one lattice constant. The propagation behavior of guided modes in these waveguide networks was probed using a network analyzer. High transmission efficiency (with loss below 0.5 dB) through various waveguide bends and networks with carefully designed geometries has been achieved.