【摘要】 用相干量子干涉和电磁感应透明(Electromagnetically induced transparency,EIT)效应在Er3+:YAlO3晶体中计算得到了Thommen,Mandel和Kastel对原子气提出的Λ型四能级系统的负折射率.计算结果得到的负折射率对应的频带宽度约为1MHz,比先前报道的103Hz量级要宽得多.通常而言对应于折射/吸收比Re[n]/lm[n]≈1,而计算所得结果是Re[n]/lm[n]为4.6,表明吸收被EIT效应很好地抑制.Im[n]出现的负值可能与Er3+的4I13/2→4I15/2跃迁的受激发射有关.由此可知,稀土离子掺杂材料具有丰富的能级和各种不同的电磁跃迁,也是电磁感应负折射率材料中出色的应用材料的候选者.更多还原

【Abstract】 We first calculated the negative refractive index on the solid Er 3+:YAlO₃ crystal with a Λ-type four-level scheme proposed for atomic vapour by Thommen and Mandel and Kastel using quantum interference and electromagnetically induced transparency（EIT）.It is shown that the frequency band with the negative index is wider（～1 MHz） than that reported previously.Usually,Im[n] is always positive,corresponding to absorption,and the ratio of refraction to absorption,Re[n]/Im[n],is only of the order of unity.In our case the ratio Re[n]/Im[n]=4.6,which indicates that the absorption has been well suppressed by EIT approach.The negative Im[n] may be related to the stimulated emission of 4I 13/2 → 4I 15/2 of rare earth ion Er 3+.It indicates that the rare earth ion doped material with abundant energy levels and various electric and magnetic transitions is an outstanding and practical candidate for electromagnetically induced negative refractive index material.更多还原