Susceptibility of a two-level atom near an isotropic photonic band edge: Transparency and band edge profile reconstruction

Abstract

h i g h l i g h t s• We consider the linear response of a driven two-level atom coupled to an isotropic band edge.• We consider atomic decay in a vacuum with a flat and a non-flat density of modes. • Transparency at certain frequencies occurs for an isotropic band gap density of modes.• The band edge density of modes can be obtained from the measured susceptibility. a b s t r a c tWe discuss the necessary conditions for a two-level system in the presence of an isotropic band edge to be transparent to a probe laser field. The two-level atom is transparent whenever it is coupled to a reservoir constituted of two parts-a flat and a non-flat density of modes representing a PBG structure. A proposal on the reconstruction of the band edge profile from the experimentally measured susceptibility is also presented.