Optical–terahertz solitons with tilted fronts

A soliton-like mode of generation of terahertz radiation by optical pulses with tilted wavefronts in a quadratic nonlinear medium has been studied. It has been shown that the formation of an optical–terahertz soliton at a positive dispersion of the group velocity above a critical value, which depends on the tilted angle, and at a negative nonlinear susceptibility in the optical range is accompanied by the generation of a terahertz unipolar soliton propagating in a different direction.