Author:
Geng Yue,Pei Xiaoshan,Li Guanrong,Lin Xinyu,Zhang Hanxiao,Yan Dong,Yang Hong
Abstract
Control of unidirectional light propagation is of paramount importantance to optical signal processing and optical communication. Especially, the amplified optical signal can isolate noise well that may provide more applications. In this work, we propose a dynamically modulated regime to realize unidirectional reflection amplification in a short and dense uniform atomic medium, and all atoms are driven into four-level double-Λ type by two coupling fields with linearly varied intensities along x direction and two weak probe fields. Based on four-wave mixing resonance and the broken spatial symmetry, the complete nonreciprocal reflection (unidirectional reflection) can be amplified with reflectivity more than 2.0, even to 6.0. In addition, the width, height, and position of the unidirectional reflection bands can be tunable. Thus, our regime is feasible and may inspire further applications in all-optical networks that require controllable unidirectional light amplification.
Funder
Specific research fund of The Innovation Platform for Academicians of Hainan Province
Nature Science Foundation of Science and Technology Department of Jilin Province
National Natural Science Foundation of China
Natural Science Foundation of Hainan Province
Subject
Atomic and Molecular Physics, and Optics