Compression of femtosecond light pulses by one-dimensional photonic crystals with two-component relaxing nonlinearity

The compression of ultrashort light pulses in a one-dimensional nonlinear photonic crystal is investigated for light frequencies lying outside the forbidden gap of a periodic structure taking into account the delayed nonlinear response of a medium. It is shown that the relatively slow-responding defocusing nonlinearity can suppress the distortion of Bragg solitons caused by the relaxation of the fast self-focusing component and improve the compression efficiency. Stable optical quasisoliton propagation of light pulses and their compression are numerically confirmed for both band gap composite materials and photonic crystals with alternating layers of different types of nonlinearity.