摘要
二阶非线性光学效应是非线性光学中人们发现最早,研究最多,应用最广的一个课题。在非对称性势阱中,二次谐波产生系数与势阱的形状及其非对称性程度有很大的关系。本文用量子力学中密度矩阵算符理论导出了Poschl-Teller势阱中二次谐波产生系数和解析表达式。考虑到在Poschl-Teller势阱中有两个可调参数κ和λ,并且势阱的形状与对称性随κ和λ取值的不同而明显不同,因此我们可以通过调节κ和λ的取值而获得Poschl-Telle势阱中的二次谐波产生系数的变化规律,并找到其最大值,从而为实验提供必要的研究方向与理论依据。
Nonlinear optics of low-dimensional semiconductor structures has recently attracted considerable attention. The problem is very important to the development of super-lattice devices such as fast infrared detectors and modulators because one needs to know the range of input optical intensities for which linear operation is possible. Analytical expression of the second-harmonic generation (SHG) coefficients is obtained in the Poschl-Teller well using the density matrix formalism taking into account the intrasubband relaxation. Since there are two adjustable parameters K and A in the Poschl-Teller well, the shape of the well will change with the change of the parameters K and A, accordingly the SHG coefficient will change with the parameters K and A. It is shown that the SHG coefficient depends on the parameter K , A and the tunnel bandwith. Numerical results are presented for a typical AlGaAs/GaAs Poschl-Teller well.
出处
《量子电子学报》
CAS
CSCD
北大核心
2003年第6期661-665,共5页
Chinese Journal of Quantum Electronics
基金
广东省教育厅自然科学研究基金(202069)
