Raman echo under conditions of medium excitation by extremely short pulses

A generalization of the Bloembergen-Shen model was supposed on cases those Raman active molecules with an arbitrary number of normal modes. On the basic of this model were investigated Raman echo signal characteristics when medium was excited by pulses of widths up to one period of optical oscillations. It was shown that a large number of echo responses on Stokes and anti-Stokes components could arise even under a two-pulse action in a continuous monochromatic pumping field. The number of echo responses depended on the number of molecular normal modes and the geometry of experiments. At small exciting pulse "areas," the echo responses whose Stokes and anti-Stokes components corresponded to normal vibrational modes of a molecule.