Layer-by-Layer 3D Photonic Crystal Waveguides and Components --- Theoretical Analysis for Microwave Implementation

A theoretical design is presented for a mode coupler that enables efficient transmission of energy from a metallic rectangular waveguide to a 3D layer-by-layer PC waveguide over a wide bandwidth at frequencies from microwave to terahertz. It is used to theoretically demonstrate a 90° bend, and a T-junction in a 3D PC. Computed results on the transmission and reflection of these components obtained using the finite-difference time-domain method are described. The design of the mode coupler will allow high quality experimental characterization of layer-by-layer components at microwave frequencies