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  

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

作　　者：陈知红[1] 方天红[1] 李钱光[1] 吕昊[1] 

机构地区：[1]湖北工程学院物理与电子信息工程学院,湖北孝感432000

出　　处：《光子学报》2015年第4期25-28,共4页Acta Photonica Sinica

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

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χ(3)DFWM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,χ(3)DFWM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.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 thirdorder 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 ofχ（3）DFWMwill shift to lower energy,and the intensities of the peaks will greatly increase.

关 键 词：非线性光学 核壳量子点 三阶极化率 极化子效应 简并四波混频 

分 类 号：O437.1[机械工程—光学工程]