Improved amplitude-frequency characteristics for T-splitter photonic crystal waveguides in terahertz regime

摘要

Based on the plane-wave expansion method, we calculate TE/TM gaps of 2-D photonic crystals (PCs) with typical square lattices composed of the silicon rods in air. Using the finite-difference time-domain method, we simulate the electromagnetic field distribution of THz waves in photonic crystals T-splitters. By the improved T-splitter with a rod in the junction, we achieved the amplitude-frequency characteristics of a pass band of 84% from 1.12 to 1.22 THz and surpassed by 76% the amplitude consistency of common T-splitters. And using the finite-difference time-domain method, we demonstrated that the improved T-splitter excels a common T-splitter in the degree of separation between the two output ports. These results provide a useful guide and a theoretical basis for the developments of THz functional components.