半导体氧化物ZnO和CdO纳米材料的光学非线性研究

【作者】 刘冠明；

【导师】 常青；

【作者基本信息】 黑龙江大学 ， 物理电子学， 2008， 硕士

【摘要】 本论文概述了非线性光学、激光防护及光限幅的发展,系统总结了近年来国内外关于半导体纳米材料的光学非线性特性的研究成果、研究方法及相应的理论分析方法。并详细介绍了单光束激光Z扫描技术。利用单光束激光Z扫描技术在波长532 nm处研究了粒子形状对三阶光学非线性特性的影响,对比了ZnO纳米棒和ZnO纳米粒子在水中悬浮液的实验。实验结果显示ZnO纳米棒的三阶非线性光学特性强于ZnO纳米粒子的三阶非线性光学特性,并显示三阶非线性光学与粒子形状有很大关联,用有效介质理论进行了解释。研究了CdO纳米线在水和乙醇悬浮液中的光限幅特性,发现在波长为532 nm的激光脉冲作用下,CdO纳米线乙醇悬浮液的光限幅特性强于CdO纳米线水悬浮液,认为其主要机制是非线性散射。更多还原

【Abstract】 In this dissertation, the development of nonlinear optics,laser protection and optical limiting are reviewed. The result of recent years, analysis methods of semiconductor materials and principle are summarized systemically. A kind of sensitive measurement of optical nonlinearities using a single beam Z-scan technique and its theoretical analysis are reviewed in details.Effects particle shape on the third-order optical nonlinearities of ZnO nanorods and ZnO nanoparticles are studied by using Z-scan technique with nanosecond pulses at 532nm.The experiment results show that the third-order optical nonlinearities of ZnO nanorods are stronger than that of ZnO nanoparitcles. Experimental results show that the third-order nonlinear optical performances strongly dependent on the shape of the nanomaterials as described by the Maxwell-Garnett Effective Medium Theory,MGT.Optical limiting(OL) properties of CdO nanowires in water and ethanol were investigated by using nanosecond laser pulses at 532nm.Experimental results show that suspension of CdO nanowires in ethanol exhibits better OL property than suspension of CdO nanowires in water.The dominant mechanism for the observed enhanced optical limiting in ethanol suspensions of CdO nanowires is due to nonlinear scattering.更多还原