The Phenomenon of Self‐Induced Transparency in the Range of the Proper Lattice Absorption

Soliton wave pulses are investigated in the phonon range of the spectrum. The phenomenon of self‐induced transparency (SIT) is considered taking into account both, the amplitude and the phase modulations of the soliton wave packets. In essence new dispersion laws and the wave vector dependence of the soliton velocity are obtained. Criteria of SIT theory application are given, and also new possibilities of observing non‐linear optical phenomena in the phonon range of the spectrum are pointed out.