EXCITATION AND RADIATION TRANSFERS IN MEDIA OF IDENTICAL 2-LEVEL ATOMS

The excitation and the radiation transfers in media with different dim ensions consisting of identical two-level atoms are examined within th e framework of the density matrix formalism, and the dependence of sel f-broadening of the spectral line shape on the dimensionality of the m edia are shown. The static approximation, i.e., the quasiordered froze n atomic system, is taken for describing the media, and it is assumed that the atoms are resonantly coupled with the radiative field and int eract with the atomic dipole field. We treat the excitation and the ra diation transfers separately in this study. It is remarkable to note t hat without an inclusion of radiation process, the excitation can show the shrinking effect on the spatial distribution, if the one-dimensio nal media are nonuniform. It is discussed that the shrinking effect ca n cause a small-sized object irradiating for a long time in a medium o f identical atoms excited by laser radiation.