光子学报 ›› 2015, Vol. 44 ›› Issue (4): 419003-0419003.doi: 10.3788/gzxb20154404.0419003

• 非线性光学 • 上一篇    下一篇

极化子效应对ZnS/CdSe柱型核壳量子点简并四波混频过程的影响

陈知红, 方天红, 李钱光, 吕昊   

  1. 湖北工程学院 物理与电子信息工程学院, 湖北 孝感 432000
  • 收稿日期:2014-09-15 修回日期:2014-11-18 出版日期:2015-04-25 发布日期:2015-04-25
  • 作者简介:陈知红(1980-),女,副教授,硕士,主要研究方向为非线性光学.Email:zhihong9905@163.com
  • 基金资助:

    湖北省教育厅青年人才项目(No.Q20142706)和湖北工程学院科学研究项目(No.z2013028)资助

Polaron Effect on the Degenerate Four-wave Mixing in a ZnS/CdSe Quantum Dot Quantum Well

CHEN Zhi-hong, FANG Tian-hong, LI Qian-guang, LÜ Hao   

  1. School of Physics and Electronic-information Engineering, Hubei Engineering University, Xiaogan, Hubei 432000, China
  • Received:2014-09-15 Revised:2014-11-18 Online:2015-04-25 Published:2015-04-25

摘要:

理论计算了带有极化子效应的ZnS/CdSe柱型核壳结构量子点简并四波混频的三阶极化率.在有效质量近似下,采用无限深势阱模型,导出了带有极化子效应的柱型量子点的三阶非线性光学极化率的解析表达式,解三维薛定谔方程得到电子的本征能量和波函数.分析了电子-LO声子和电子-IO声子相互作用对ZnS/CdSe核壳结构量子点简并四波混频的三阶极化率的影响.结果表明,当量子点尺寸一定时,带有极化子效应的χDFWM(3)比没有极化子时的三阶极化率提高了近3个数量级,并且电子-LO声子的影响比电子-IO声子的影响大得多;当固定核壳量子点的阱宽而内外半径发生变化时,χDFWM(3)的峰值随之变化,而且极化子效应影响的大小也随之发生变化.

关键词: 三阶极化率, 核壳量子点, 简并四波混频, 非线性光学, 极化子效应

Abstract:

The effect of the electron-phonon interaction on the degenerate four-wave mixing was investigated theoretically for electrons confined in a core-shell quantum dot.Under the framework of effective-mass approximation,the interactions of electrons with different phonon modes in the core-shell system,including the confined longitudinal optical and the interface optical phonon modes,were investigated.The degenerate four-wave mixing on a ZnS/CdSe core-shell quantum dot as a function of pump photon energy with different incident photon energy and under different sizes was calculated.The results reveal that the polaron effects are quite important especially around the peak value of the third-order susceptibility.The influence of electron-LO-phonon interaction on the degenerate four-wave mixing is bigger than the influence of electron-IO-phonon interaction.By increasing the size of the quantum dots,the peaks of χDFWM(3) will shift to lower energy,and the intensities of the peaks will greatly increase.

Key words: Third-order optical susceptibilities, Nonlinear optics, Degenerate four-wave mixing, Core-shell quantum dot, Polaron effect

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