Abstract
The parametric down conversion of the light wave induced by stimulated polariton scattering in polar crystals is investigated from the aspect of long wave short wave interaction. Assuming that the light wave is the superposition of short wave (near-infrared light) and long wave (terahertz wave), time-evolution equations for the long wave and the envelope of the short wave are derived by means of a reductive perturbation method. Further, depending on the crystal properties, these equations describe two different situations. In one situation, the nonlinear effect of the short wave is dominant. In the other situation, the dispersion effect of the long wave is significant. For both cases, linear stability analysis is applied to the equations, and traveling wave solutions are obtained.
