Effect of selective saturated absorption on atomic line filter

We report an atomic filter based on optical pumping induced anisotropy in Doppler-broadened two-level atoms. Atomic line filters (ALF) in previous research used a selective pump to populate atoms on special Zeeman sub-levels to obtain optical anisotropy because of dipole selection rules. Unlike them, we proposed a novel method to get circular anisotropy realized by selectively saturated absorption in rubidium.