The polarization dependence of double-resonance optical pumping (DROP) in the ladder-type electromagnetically induced transparency (EIT) of the $5{S}_{1/2}\ensuremath{-}5{P}_{3/2}\ensuremath{-}5{D}_{5/2}$ transition of
87Rb atoms is studied. The transmittance spectra in the $5{S}_{1/2}(F=2)\ensuremath{-}5{P}_{3/2}({F}^{\ensuremath{'}}=3)\ensuremath{-}5{D}_{5/2}({F}^{\ensuremath{'}\ensuremath{'}}=2,3,4)$ transition were observed as caused by EIT, DROP, and saturation effects in the various polarization combinations between the probe and coupling lasers. The features of the double-structure transmittance spectra in the $5{S}_{1/2}(F=2)\ensuremath{-}5{P}_{3/2}({F}^{\ensuremath{'}}=3)\ensuremath{-}5{D}_{5/2}({F}^{\ensuremath{'}\ensuremath{'}}=4)$ cycling transition were attributed to the difference in saturation effect according to the transition routes between the Zeeman sublevels and the EIT according to the two-photon transition probability.
An experimental investigation of the Cs $6s\phantom{\rule{0.2em}{0ex}}^{2}S_{1∕2}\ensuremath{\rightarrow}6p\phantom{\rule{0.2em}{0ex}}^{2}P_{3∕2}\ensuremath{\rightarrow}10s\phantom{\rule{0.2em}{0ex}}^{2}S_{1∕2}$ double-resonance two-photon polarization spectrum has been made. In the investigation, a linear polarization degree was measured to extract the alignment depolarization cross section in the cesium
6p2P3∕2 level due to collisions between ground-level argon and excited
6p2P3∕2 cesium atoms over the Zeeman coherences. The spectra show strong depolarization of the Cs
6p2P3∕2 level. The measured alignment depolarization cross section value of 186
(58)A˚2 is in good agreement with the experiment and theoretical predictions.