Coherent emission generated in time-separated fields with the aid of hyperfine structure levels

The amplitude and polarization are found for the first coherent radiation pulse generated in time-separated fields with the aid of resonant levels exhibiting a hyperfine structure. It is shown that such hyperfine splitting of the resonant levels does not alter qualitatively the conclusion that it should be possible to observe narrow structures in the intensity of such a pulse under conditions of scanning of the frequency of the exciting pulses. This feature is important because of possible technical applications of such narrow structures. The polarization properties of the first coherent radiation pulse generated in time-separated fields depend strongly on whether one or all hyperfine components of each of the resonant levels participate in the formation of a pulse.