Velocity selective optical pumping effects in electromagnetically induced absorption for $^{\mathrm{85}}$Rb atoms: polarization dependences*

We present experimental and theoretical studies on velocity selective optical pumping effects on electromagnetically induced absorption for the F$_{\mathrm{g}}=$3$\to $F$_{\mathrm{e}}=$2,3, and 4 transitions of $^{\mathrm{85}}$Rb atoms. Probe transmittance spectra are investigated by scanning the coupling laser frequency from the F$_{\mathrm{g}}=$3$\to $F$_{\mathrm{e}}=$2,3, and 4 transitions with a weak probe laser resonant to the F$_{\mathrm{g}}=$3$\to $F$_{\mathrm{e}}=$4 transition of $^{\mathrm{85}}$Rb atoms. We consider laser linewidth, atomic thermal velocity distributions, frequency mixings of coupling and probe beams due to degenerate magnetic sublevels, and various polarization configurations of the coupling beam with a probe beam fixed at $\sigma^{\mathrm{+}}$ polarization in the simulation of the spectra. We find good agreement between the calculated and observed transmittance spectra for each coupling laser polarization configuration.