Spectra of pulses propagating in atomic media in the closed double Lambda configuration

摘要

Simultaneous propagation of two probe pulses in a medium of four-level atoms irradiated by three control fields is studied. The double. configuration has been closed by a fifth field, coupling the lower levels. It is shown that the propagation can be described in terms of four modes characterized by particular effective susceptibilities, which have absorption or gain peaks and transparency windows. For incoming one-peak pulses, multipeak spectra are built during the propagation including a few components of well-defined frequencies. They evolve along the sample with some of their spectral components being transmitted, absorbed, or amplified. (C) 2014 Optical Society of America