On generation of terahertz radiation in the self-induced transparency regime in a system of impurities with a permanent dipole moment

The article deals with the resonant mechanism of the generation of terahertz radiation based on the interaction between a laser pulse and two-level quantum particles with a permanent dipole moment. In the case when the permanent dipole moment exceeds the transition dipole moment, the resonant mechanism is more efficient compared to the nonresonant optical rectification.