Analysis of Leakage Losses in One-Dimensional Photonic Crystal Coupled Resonator Optical Waveguide Using 3-D Finite Element Method

We have evaluated leakage losses of one-dimensional photonic crystal coupled resonator optical waveguides (1-D PC-CROW) by using three-dimensional finite element method (3-D FEM). We propose structure of 1-D PC-CROW with shifted position of air-hole, changed size of air-hole, and changed air-hole depth. We have also proposed air-bridge 1-D PC-CROW and evaluated group velocity and leakage losses of these CROWs. Our numerical results show that 1-D PC-CROW has large leakage losses, especially for vertical direction, and the proposed structure can reduce leakage losses. Leakage loss of 1-D PC-CROW with changed air-hole depth is two order of magnitude lower compared with normal structure.