Interference spectra in four-level atomic systems

摘要: We have calculated the interference spectra of a single electron in excited state four-level atom interacting with three laser fields, where two them are on two-photon resonance levels forming `Λ' scheme while third operates between second ground and states atom. It is shown that low-intensity limit all field destroys destructive occurs spontaneous radiative decay process arising from combined fields. The result overall intensity peak at centre line depends strength it takes negative values indicating light amplification without population inversion (LAWI) likely to occur one-photon frequency. antisymmetric lower as well process, one photon absorbed another emitted simultaneously by atom, found exhibit LAWI derived results graphically presented discussed.