用HRS技术研究CdS/Cd纳米粒子的二阶光学非线性
Research on the Second Order Optical Nnonlinearity of Nanoparticles by Hyper-Rayleigh Scattering Technique
作者单位
付德刚 东南大学分子与生物分子电子学教育部重点实验室, 南京210096 
张宇 东南大学分子与生物分子电子学教育部重点实验室, 南京210096 
汪昕 东南大学分子与生物分子电子学教育部重点实验室, 南京210096 
成济齐 东南大学分子与生物分子电子学教育部重点实验室, 南京210096 
刘举正 东南大学分子与生物分子电子学教育部重点实验室, 南京210096 
陆祖宏 东南大学分子与生物分子电子学教育部重点实验室, 南京210096 
摘要: 用新发展的超瑞利散射(HRS)技术(一种非相干的方法)研究了表面富镉的CdS纳米粒子的二阶非线性光学性质。结果表明每个纳米粒子的二次非线性极化率β值在10-26esu量级,这在目前报导的具有最大β值的溶液物种之列。探讨了CdS纳米粒子产生二阶非线性的机制。认为纳米粒子大的比表面及表面缺陷结构对CdS纳米粒子的二阶光学非线性有很大影响。另外,双光子吸收诱导的共振增强作用亦可能贡献CdS纳米粒子的HRS信号,这种双光子共振吸收被其双光子荧光谱所证实。
关键词: 二阶非线性光学(NLO)  超瑞利散射(HRS)  纳米粒子
基金项目: 国家自然科学基金资助项目(No.29874008);教育部回国留学人员基金资助课题.
Abstract: The second order optical nonlinearity of surface Cd-rich CdSnanoparticles has been studied by newly developed Hyper-Rayleigh Scattering technique(an incoherent methodology).The results indicated that the first hyperpolarizability β per particles was 1.3×10-26esu for CdSnanoparticles in sum diameter.This value is in the largest values reported for solution species.The HRSmechanism of nanoparticles was discussed.It is believed that the surface layer is the main origin of second order optical nonlinearity in nanoparticles.Especially the Cd-Sbonding on the surface of the CdS/Cd nanoparticles act as molecule-like scatters, while surface defects such as dislocations, vacancies, dangling orbitals, surface chemical species etc make surface layer highly polarizable.Further more, the HRS signal of CdS nanoparticles was also enhanced by two-photo absorption as viewed from fluoresecence spectrum.
Keywords: second order optical nonlinearity  hyper-rayleigh scattering(HRS)  nanoparticles
投稿时间:2001-03-06 修订日期:2001-03-22
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付德刚,张宇,汪昕,成济齐,刘举正,陆祖宏.用HRS技术研究CdS/Cd纳米粒子的二阶光学非线性[J].无机化学学报,2001,17(3):395-400.
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