Self-focusing of few-cycle light pulses in dielectric media

Various scenarios of self-focusing of axisymmetric few-cycle light pulses in optical media with nonresonant dispersion and nonlinearity are investigated numerically. It is shown that the spatiotemporal dynamics leads to the formation of complex light structures like dumbbells or bubbles depending on the initial intensity. The bubble includes a center area with emptiness, where the electrical field is practically nullified. An analysis is made of the characteristics of spectral supercontinuum generation accompanying the dispersive self-focusing. The development of a broad blueshifted spectral wing during the breakdown of a shock wave of the pulse profile is considered in detail.