用分数维空间方法研究量子阱中激子效应对三次谐波产生的影响

J4 ›› 2011, Vol. 28 ›› Issue (4): 473-482.

用分数维空间方法研究量子阱中激子效应对三次谐波产生的影响

于凤梅¹,李伟¹,郭康贤²

1 仲恺农业工程学院信息学院，广东广州 501225； 2 广州大学物理与电子工程学院广东广州 510006

收稿日期:2011-01-04 修回日期:2011-04-11 出版日期:2011-07-28 发布日期:2011-07-06
通讯作者: 于凤梅（-1976），女，辽宁丹东人，讲师，硕士，研究方向主要为低维半导体结构中的非线性光学效应。 E-mail:yufengmei401@126.com
基金资助:
Supported by Foundation for Distinguished Young Talents in Higher Education of Guangdong ( LYM08068) and Science and Technology Plan Projects in Guangdong Province ( 2010A080802002, 2010B080704002, 2010B090400130）

Excitonic effects on third-harmonic generation in quantum wells via a fractional-dimentional space approach

YU Fengmei¹, LI Wei¹，GUO Kangxian²

1 Information College, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China；
2 Department of Physics, College of Physics and Electronic Engineering, Guangzhou University, Guangzhou 510006, China

Received:2011-01-04 Revised:2011-04-11 Published:2011-07-28 Online:2011-07-06
Supported by:
Supported by Foundation for Distinguished Young Talents in Higher Education of Guangdong ( LYM08068) and Science and Technology Plan Projects in Guangdong Province ( 2010A080802002, 2010B080704002, 2010B090400130）

摘要/Abstract

摘要：

运用分数维空间方法理论研究了GaAs/AlGaAs无限深和有限深方形量子阱中激子效应对三次谐波产生的影响。利用分数维空间模型获得波函数和束缚能级为空间维度的函数，而空间维度数是阱宽的函数。无限深方阱的维度数随着阱宽的减小从三维极限过渡到二维；而在有限深阱中，当维度数达到一个极值后，维度数随阱宽的减小而增大。采用密度矩阵和迭代法导出三次谐波的表达式。数值结果表明，考虑激子效应的三次谐波系数比只考虑电子状态的系数增大40%左右，并且三次谐波系数大小依赖于激子的受限程度。结果还表明在弛豫率较小情况下可以获得较大的三次谐波的系数。

关键词: 非线性光学, 三次谐波, 分数维空间, 激子效应, 量子阱

Abstract:

Exciton effects on the third-harmonic generation in GaAs/AlGaAs infinite and finite square quantum wells are calculated within the framework of the fractional-dimensional space approach. The wave functions and bound energies are obtained as functions of spatial dimensionality and the dimension is a function of the well width. For an infinite confining potential the dimension (D) has a transition from the 3D limit to the 2D limit when the well width decreases. However, in a finite well, when the well width decreases below a given value, the dimension increases. The analytical expression of the third-harmonic generation is described using the compact density method and the iterative procedure. The numerical results show that the third-harmonic generation coefficient with considering exciton effects is 40% greater than the one without considering exciton effects and it is very sensitively dependent on the exciton confinement. In addition, the smaller the relaxation constant is, the larger the third-harmonic generation will be.

Key words: nonlinear optics, third-harmonic generation, fractional-dimensional space, exciton effects, quantum wells

中图分类号:

O437

于凤梅李伟郭康贤. 用分数维空间方法研究量子阱中激子效应对三次谐波产生的影响[J]. J4, 2011, 28(4): 473-482.

YU Fengmei, LI Wei，GUO Kangxian. Excitonic effects on third-harmonic generation in quantum wells via a fractional-dimentional space approach[J]. J4, 2011, 28(4): 473-482.

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