Zakharov-Benney resonance as a mechanism for generating extremely short pulses in uniaxial crystals

The possibility of generating an extremely short (without high-frequency filling) pulse of an extraordinary wave in a uniaxial crystal by means of nonlinear interaction with a quasi-monochromatic ordinary wave in the regime of Zakharov-Benney resonance is discussed. It is shown that the appropriate conditions can be created in crystals with positive birefringence, and stable extremely short extraordinary solitons can be created in the spectral range of normal dispersion at the threshold intensity of input pulse on the order of $10^{13}-10^{14}\,$W/cm$^2$.