Joint Institute for Nuclear Research , Russia

We discuss the possibility of generation of optical-terahertz solitons by optical rectification in quadratically nonlinear media. The bound state of an optical laser pulse and a terahertz few cycle pulse becomes possible due to Zakharov-Benney resonance. The conditions of soliton stability in bulk medium are determined by variational approach. We also consider the regimes of nonelastic collisions of co-propagating solitary waves in such system. The pulse group velocity and frequency can be changed during the interaction. The effects of pulse reflection, tunneling, blocking and trapping are found by variational approach and numerical simulations.