Low cross-talk waveguide intersections for TE polarization using photonic crystals

摘要： In this paper, two low cross-talk and wide bandwidth waveguide intersections are proposed based on novel types of resonators which are created using rotated photonic crystal lattices. A lattice of the air holes in a GaAs substrate is used to realize the waveguides. By inserting a second lattice of holes which resembles the main lattice, with a particular amount of scaling and rotation, we have created a resonator which can diminish the cross-talk in waveguide intersections. Two new topologies have been proposed based on the mentioned resonators, one with two sets of waveguides (four arms) and the other one with three sets of the waveguides (six arms). Plane wave expansion (PWE) and finite difference time domain (FDTD) methods are used for numerical simulation of the intersections. Simulation results indicate that a bandwidth of 49.1 nm and a cross-talk level of -40 dB can be obtained for the intersection of two waveguides using the configuration proposed in this paper.