Eliminating excess phase accumulation in a continuous perturbed heterogeneous planar photonic crystal

We propose an asymmetric distribution of a hexagonal lattice for achieving near-zero group velocity with negative delay. This study reports the effect continuous geometric perturbation on photonic band diagram and consequently its impact phase velocity, effective refractive index. provide promising method modifying to obtain exotic dispersion diagram. With this broadband spanning from E L band, light pulse envelope travels almost zero is application in wide variety light-based devices.