Eu^(3+):Y_2SiO_5晶体中射频场耦合四能级系统的电磁感应吸收和透明

Electromagnetically Induced Absorption and Transparency of Four-Level System Driven by Radio-Frequency Field in Eu^(3+)\:Y_2SiO_5 Crystal

在Eu3+:Y2SiO5晶体中,以射频场耦合自旋子能级的方式,得到一个四能级系统。运用密度矩阵方程,研究了该射频场耦合四能级系统的吸收特性。结果表明,由于光学耦合场和射频场的共同作用,探测吸收谱可分别呈现出电磁感应透明(EIT)和电磁感应吸收(EIA)这两种相反的量子效应。当射频场共振作用时,在射频场导致的Autler-Townes分裂的双峰区域内出现EIT效应;非共振时,又会出现EIA效应。EIT和EIA窗口位置决定于光学耦合场的频率失谐量。改变射频场和光学耦合场的拉比频率、失谐量等参数,可以实现EIT和EIA窗口位置、线宽,以及这两种效应之间的转换控制。

A four-level system in Eu3＋／：Y2SiO5 crystal is obtained through coupling a hyperfine level with a radio-frequency field.The absorption properties of this four-level system driven by a radio-frequency field are investigated by means of density matrix equation of motion.It is shown that the two contrary quantum effects,electromagneticically induced transparency（EIT） and electromagnetically induced absorption（EIA） can be obtained in the absorption spectrum of the system due to the interaction of both optical coupling and radio-frequency fields.When radio-frequency field resonates with corresponding levels,EIT effect presents within two-peak area of Autler-Townes splitting caused by radio-frequency field.But nonresonant radio-frequency field can cause EIA.The positions of EIT and EIA are determined by the detuning of optical coupling field.The linewidth,position and conversion of EIT and EIA can be controlled by changing detuning,Rabi frequency of optical coupling and radio-frequency fields.