Electromagnetically Induced Transparency in the Five-level Scheme of Cold \(^{85}\)Rb Atomic Vapour

In the framework of the semiclassical theory, we develop an analytical approach on electromagnetically induced transparency (EIT) in the medium consists of five-level cascade scheme of cold 85 Rb atoms. In the weak field limit of the probe light, an analytical representation of EIT spectra is derived for the first time. Signatures of EIT spectra, including transparency efficiency, have been investigated. We see a tremendous agreement between our theoretical results and experimental observations.