Crosstalk Reduction in Square Cavities

Theoretically and experimentally, we demonstrate that low crosstalk between two crossed line-defect waveguides formed in a square lattice photonic crystal (PC) structure can be achieved using a resonant cavity at the intersection area. The PC resonator consists of cubic air-holes in silicon air-holes. The Q-factor of the cavity can be changed by increasing the number of holes that form the cavity. The theoretical and experimental crosstalk results are about -40 dB and -20 dB, respectively.