Abstract
We investigate the absorption and dispersion spectra of the light pulse propagation through Doppler broadened driven qubit by exponentially weak decaying field in the presence of an off-resonant broadband squeezed vacuum (SV) reservoir. Combined effects of Doppler broadening and SV reservoir parameters induce
enhanced
sub- and super-luminal behavior of light through the qubit medium, as compared with the normal vacuum (NV) and thermal field (TF) reservoir cases. The SV phase, as a control parameter, induce enhanced sinusoidal (positive and negative) peaks of group index of the Doppler broadened medium.