Compression of ultrashort light pulses in photonic crystals: when envelopes cease to be slow

A modification of the transfer-matrix method and the nonlinear finite-difference time-domain technique are applied to simulate the propagation of ultrashort laser pulses in linear and nonlinear one-dimensional photonic band gap (PBG) structures. Dispersion properties of photonic crystals allow the chirp of a short light pulse to be compensated in a controlled fashion. It is demonstrated that photonic crystals with embedded optical nonlinearity provide an opportunity to efficiently compress laser pulses to a duration of several optical cycles on a submillimeter spatial scale, providing new opportunities for the miniaturization of femtosecond solid-state laser systems. Physical factors limiting the minimum duration of compressed pulses are studied for such structures and the ways to optimize pulse compression are discussed. Examples of PEG pulse compressors that can be fabricated by means of currently existing technologies are considered. (C) 1999 Published by Elsevier Science B.V. All rights reserved.