Abstract:
A solution is obtained for the equations describing the passage of a monochromatic radiation pulse of arbitrary shape I0(t) across a two-level absorbing medium with an activeparticle density N0 = const. It is shown that, depending on the ratio of the velocity of the medium v(t) to v0 = 2I0/N0, two modes of propagation of bleaching waves can be observed and the boundary between these modes is v = v0. The treatment is applicable to a radiation source moving at an arbitrary velocity in an absorbing medium.