Double EIT and enhanced EIT signal in a combination of Λ- and V-type system of Rb-D2 transition

We report the experimental observations of double EIT and enhanced EIT signal in a combination of Λ- and V-type multi-level system of the D2 transition of 85Rb atoms interacting with three laser fields. The EIT formation under a Λ-type and V-type systems is also observed separately. It is found that the EIT width in a V-type system becomes narrower than the Λ-type system. Also the effect of frequency detuning of the control laser on the probe absorption profile is studied in presence of Λ- and V-type EIT systems.