Optical pumping effects on high-contrast Rydberg electromagnetically induced transparency

We provide a universal discussion of the interplay between Rydberg-state electromagnetically induced transparency (EIT) and optical pumping (OP) in thermal Rb87 medium. By population to one single Hyperfine/Zeeman state, we can enhance interaction strength and, principle, amplify EIT peak. According our measurements, peak height be improved by factor two or reduced order magnitude, linewidth was slightly narrowed effect. Similar behavior is also seen increasing density (OD) The feature predicted quantitatively using Doppler-free non-perturbation numerical calculation. With without field, heights collapse onto same theoretical curve, showing that OP varying OD have In both simulations Rydberg enhancement through dependent on intensity probe field OD. Our work clarifies underlying mechanisms advances Rydberg-atom research.