The method of optical signal generation with repetition rate frequency of about 30-50 THz based on interaction of two femtosecond laser pulses propagating collinearly in transparent nonlinear media with different group velocities is presented. It was shown that for high input pulses intensities their interaction may result in formation of quasi-discrete spectrum with temporal structure consisting of many ultrashort pulses of near rectangular shape. It was demonstrated that generated sequence could be used in information technologies.
A new wave equation for the electrical field evolution of intensive femtosecond light pulses in isotropic transparent media is presented. It is demonstrated that a 'light bubble' can evolve from a few-optical cycle pulse propagating through a fused silica bulk. The two-octave spectrum supercontinuum is theoretically observed.