碳纳米管的非线性光学特性研究

发布时间：2018-04-18 08:28

本文选题：非线性光学 + 非线性吸收　；参考：《黑龙江大学》2015年硕士论文

【摘要】：为了深入研究多壁碳纳米管的三阶光学非线性,我们合成了多壁碳纳米管水溶液、多壁碳纳米管三氯甲烷溶液、多壁碳纳米管乙醇溶液以及多壁碳纳米管异丙醇溶液。但实验中,由于碳纳米管在溶液中易团聚,很难均匀分散在不同的溶剂中,严重的制约了碳纳米管的非线性效果,因此,为了更好研究碳纳米管的三阶非线性光学特性,我们首先要研究其分散的方法,为此,实验中我们采用的是十二烷基苯磺酸钠,并通过反复测量得出其最佳比例约为1:10。本文我们主要介绍了Z扫描技术、4 f相位相干成像技术和泵浦探测技术,并用这三种技术对碳纳米管的三阶光学非线性进行了深入的研究。对于皮秒Z扫描,我们测量了不同能量的多壁碳纳米管异丙纯溶液,结果表明,其饱和吸收随着能量的不断增加逐渐增强,对于非线性折射其谷值受到了抑制,并逐渐消失,而峰值得到了增强。同时,我们还研究了不同线性透射率S对多壁碳纳米管三氯甲烷溶液的影响,当S越小时,峰谷差值越明显,S越大,则Z扫描的测量精度越低。对于飞秒Z扫描,我们测量了不同能量的多壁碳纳米管氯仿溶液,结果发现,该实验过程同时含有两种吸收,即饱和吸收与反饱和吸收,同时,反饱和吸收随着能量的不断增加而增强,这是由于基态电子共振与载流子吸收相互竞争的结果。为了检验Z扫描结果的正确性,我们采用4 f相位相干成像技术对样品进行了检测,从实验结果可以看出,CCD所呈现出的均为中心亮、周围暗的图像,可以判定为自聚焦,这与Z扫描实验结果完全一致。本文最后还对多壁碳纳米管三氯甲烷等溶液采用泵浦探测技术进行了测量,经过反复实验,但样品溶液却没有表现出良好的超快动力学过程。
[Abstract]:In order to study the third order optical nonlinearity of multiwalled carbon nanotubes (MwCNTs), we have synthesized the aqueous solution of MwCNTs, the methylene chloride solution of MWNTs, the ethanol solution of MWNTs and the isopropanol solution of MWNTs.However, because carbon nanotubes are easy to agglomerate in solution, it is difficult to disperse them in different solvents, which seriously restricts the nonlinear effect of carbon nanotubes. Therefore, in order to better study the third-order nonlinear optical properties of carbon nanotubes,For this reason, we use sodium dodecylbenzenesulfonate in the experiment, and the optimum ratio is about 1: 10 by repeated measurement.In this paper, we mainly introduce the Z-scan technique, 4f phase coherent imaging technique and pump detection technique, and use these three techniques to study the third-order optical nonlinearity of carbon nanotubes.For picosecond Z scan, we measured the iso-propyl pure solution of multi-walled carbon nanotubes with different energies. The results show that the saturation absorption increases with the increasing of energy, and the valley value of nonlinear refraction is restrained and gradually disappeared.The peak value was increased.At the same time, the influence of different linear transmittance S on the trichloromethane solution of multi-walled carbon nanotubes is studied. When S is smaller, the difference between peak and valley is more obvious, and the measurement accuracy of Z scan is lower.For femtosecond Z scan, we measured the chloroform solution of multi-walled carbon nanotubes with different energies. It was found that the experimental process consists of two kinds of absorption, saturated absorption and reverse saturation absorption, at the same time,The reverse saturation absorption increases with the increase of energy, which is due to the competition between ground state electron resonance and carrier absorption.In order to verify the correctness of Z scan results, we use 4 f phase coherent imaging technique to detect the samples. From the experimental results, we can see that the images of CCD are all center bright and dark around, which can be judged as self-focusing.The results are in good agreement with the Z scan results.In the end, the pump detection technique was used to measure the multi-walled carbon nanotube trichloromethane and other solutions. After repeated experiments, the sample solution did not exhibit a good ultrafast kinetic process.
【学位授予单位】：黑龙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.11;TB383.1

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