非对称耦合量子阱中的光学克尔效应研究(英文)

The optical Kerr effect in asymmetric coupled quantum wells

详细研究了GaAs/AlxCa1-xAs非对称耦合量子阱的光学克尔效应,并利用紧束缚密度矩阵方法及迭代法导出了光学克尔效应的解析表达式.数值结果表明,入射光强、弛豫率和结构参数(如势垒宽度和右阱宽度)对光学克尔效应有明显的影响;通过优化入射光强、弛豫率和结构参数,可以获得比量子盘模型的克尔系数大四个数量级的克尔系数,其显著增强的主要原因是极大的偶极跃迁矩阵元和三阶共振条件.

The optical Kerr effect（OKE） in GaAs/AlxGa1-xAs asymmetric coupled quantum wells（ACQWs） is studied in detail.An analytic formula for the OKE in the model is obtained by a compact density matrix approach and an iterative procedure.Finally,the calculated results show the incident optical intensity,the relaxation rate and the structure parameters such as the barrier width and the right-well width have a great influence on the OKE in the system.Another important point is that the maximum OKE over 5.08×10-11 m2·V-2 can be obtained by optimizing the incident optical intensity,the relaxation rate and the structure parameters,which is over four orders of magnitude greater than in quantum disk model.The contributors to the very giant OKE include the very large dipole transition matrixes and the triple resonant condition.