Gain assisted large-scale tunable atomic filter based on double selective optical pump induced dichroism

A gain assisted large-scale tunable optical filter scheme via double selective optical pump induced dichroism is proposed. Theoretical model predicts that the filter provides a huge gain for the weak probe light, furthermore, its tunability can reach over gigahertz while its bandwidth is only several hundred megahertz, which is important for laser communication and lidar systems subjected to large Doppler shift.