| Abstract [eng] |
The objective of this dissertation is investigation of filamentation and supercontinuum generation in ordered monocrystalline and disordered polycrystalline or polydomain nonlinear media, possessing, both, the intrinsic-cubic and quadratic second-order nonlinearity, by use of femtosecond infrared laser sources with wavelengths, which fall into the normal, zero and anomalous GVD regions of the materials. In this work, it is demonstrated that filamentation in BBO crystal during type-I phase-mismatched second harmonic generation is accompanied by ordinarily polarized controllable supercontinuum generation along with extraordinarily polarized phase-mismatched second harmonic at a fixed wavelength, and self-phase matched second harmonic with a tunable wavelength. The latter phenomenon is shown to exhibit incident pulse splitting into two sub-pulses in the normal group velocity dispersion region, and spatial and temporal transformation into a light bullet in the anomalous group velocity dispersion region. Finally, it is demonstrated that supercontinuum generation in disordered polycrystalline zinc-blende media is accompanied by multiple broadband even and odd harmonics resulting in spectra spanning several optical octaves. The most striking feature being that the blue-shifted portion of the SC spectra in such materials is only limited by the number and spectral broadening of even and odd harmonics generated in the media. |
