Propagation of intrinsic chirped sub-cycle and single-cycle pulses in a silica fiber

The propagation of Gaussian sub-cycle and single-cycle pulses in a nonlinear media is studied using the analytical expression of pulses. The analytical expression is a modified version of the vector potential definition model of sub-cycle pulse. The intrinsic characteristics of sub-cycle and single-cycle pulses, such as the intrinsic chirp and the self-induced blue-shift of the central frequency of spectrum are found to have an important effect on the propagation of pulses in the nonlinear media. The initial 0.28-cycle pulse evolves into a primary multi-cycle pulse and a single-cycle precursor pulse during the propagation. The single-cycle precursor pulse is formed by the carrier frequency modulation on the leading side of pulse. During the propagation of the sub-cycle pulse, the self-steepening effect and the amplitude of the precursor pulse are more significant due to the shorter pulse duration. The reason can be attributed to the intrinsic characteristics of sub-cycle pulse. (C) 2015 Elsevier B.V. All rights reserved.