相干场和信号场对四能级负折射率原子系统的影响  

The Effects of Coherent Field and Signal Field on the Negative Refraction in a Four-level Atomic System

作　　者：任海红[1] 张惠芳[1] 白丽华[1] 郭宇[1] 张泽铭[1] 

机构地区：[1]上海大学理学院物理系,上海200444

出　　处：《光电子技术》2012年第4期267-272,共6页Optoelectronic Technology

摘　　要：根据Thommen等人提出的四能级高密原子气体模型[20],应用强相干场,实现了电磁诱导左手效应并伴随着零吸收高折射率。同时,研究了外加相干场、信号场及失谐对左手效应的影响。结果发现,介质的介电常数和磁导率同时为负的频段(即双负频段)随着相干场和失谐的Rabi频率的增加而变宽;同时,随着相干场Rabi频率的增加,介质出现了零吸收,并且在零吸收点附近出现了高的负折射率。然而,信号场如果过大,相反地会增加吸收,并且双负频段也会减小。The electromagnetically induced left-handedness with zero absorption and large negative refractive index in a dense atomic vapor medium is carried out with a fourqevel system which is proposed by Thommen et al. It is found that, with the increasing of the Rabi frequencies of coherent field and detunings, the frequency region with simultaneously negative permittivity and negative permeability widens. At the same time, zero absorption can be obtained by increasing the Rabi frequencies of coherent field. However, an excessive signal field intensity will increase the absorption and reduce the frequency region with simultaneously negative permittivity and negative permeability.

关 键 词：量子光学 人工超材料 光学相干效应 强场过程 

分 类 号：O431.2[机械工程—光学工程]