Propagation of self-collimated ultrashort pulses in a hybrid photonic crystal

Abstract

We report the propagation of self-collimated ultrashort Gaussian pulses in a hybrid photonic crystal structure, in which broadband super-collimation was proposed recently. To choose their center frequencies, we compute group velocity dispersion and third-order dispersion as a function of frequency. Using the finite-difference time-domain method, we simulate the propagation of the pulses at two frequencies, one for zero group-velocity-dispersion and the other for optimized super-collimation. It is shown that the pulses nearly retain their transverse and longitudinal shapes during propagation over a long distance, and that third-order dispersion affects the pulse shape at zero group-velocity-dispersion frequency.