Linear and Nonlinear Optics of Broad-Band Laser Pulses: Diffraction.

The typical spectrally limited laser pulse in the near-infrared region is narrow-band up to 40-50 fs. Its spectral width Δ is much smaller than the carrying wavenumber (Δ ≪ ) . For such kinds of pulses, on distances of a few diffraction lengths, the diffraction is of a Fresnel's type and their evolution can be described correctly in the frame of the well-known paraxial evolution equation.

Avalanche parametric conversion and white spectrum generation from infrared femtosecond pulses in glasses.

The observation of discrete lines in the white spectrum at the initial stage of filamentation of powerful femtosecond laser pulses, propagating in silica glasses, as well as the filamentation without plasma channels observed in the experiments in air, pushed us to look for other nonlinear mechanisms for describing these effects. In this paper, we present a new parametric conversion mechanism for asymmetric spectrum broadening of femtosecond laser pulses towards higher frequencies in isotropic media. This mechanism includes cascade generation with THz spectral shift for solids and GHz shift for gases.

Electromagnetic shock wave in nonlinear vacuum: exact solution.

An analytical approach to the theory of electromagnetic waves in nonlinear vacuum is developed. The evolution of the pulse is governed by a system of nonlinear wave vector equations. An exact solution with its own angular momentum in the form of a shock wave is obtained.