基于碳纳米粒子的非线性散射激光防护技术研究

发布时间：2018-04-09 15:15

本文选题：激光防护　切入点：数值模拟　出处：《南京航空航天大学》2017年硕士论文

【摘要】：随着激光武器技术的飞速发展,对激光防护技术的要求也在不断提高,这极大地促进了激光防护技术的发展与进步。目前,利用基于非线性光学原理的光限幅技术来实现激光防护是研究的最多、最有应用前景的技术途径之一,在对高强激光防护方面起着至关重要的作用。基于碳纳米粒子悬浮液的非线性光散射效应的防护技术就是其中的一种防护方法。本论文以碳纳米管和碳纳米粉的水和乙醇悬浮液为研究对象,基于热传导理论和等效球的米散射理论,对悬浮液的光限幅过程进行了数值模拟,研究了悬浮液厚度、浓度、溶剂种类及入射光波长等因素对其限幅性能的影响;对影响其限幅性能的各因素进行了实验验证,并结合非线性光限幅原理对其进行了分析;同时为获得稳定的悬浮液,对碳纳米管在水中的分散性能进行了实验研究。论文的主要研究内容和成果如下:1.碳纳米粒子悬浮液光限幅性能的数值模拟。在光限幅过程中,基于热传导方程和米散射理论对悬浮液中微气泡的形成、散射相位特性、散射系数及透过率进行了数值模拟,对悬浮液的厚度、浓度、溶剂种类及入射光波长等影响其限幅性能的因素进行了数值模拟,获得了悬浮液的限幅特性与这些因素的关系,为后续实验提供指导。2.对碳纳米管在水相介质中的分散性能进行了研究。综合利用了单因素实验和正交实验方法,探讨了超声时间、分散剂种类、分散剂浓度和pH值对碳纳米管在水相介质中分散性能的影响,并对其进行了分析,得到了分散的最优参数,配制出了分散效果良好的稳定悬浮液,为后续光限幅效果的实验研究奠定了基础。3.分别对碳纳米管和碳纳米粉的水及乙醇悬浮液的光限幅性能进行了实验研究,分析悬浮液的厚度、浓度、容器壁厚、粒子种类、溶剂种类、入射光波长及重复频率对其光限幅性能的影响。相同厚度下,分别对相同浓度和不同浓度的碳纳米粉和碳纳米管悬浮液进行组合时的限幅效果进行实验研究。用透光率来描述悬浮液的限幅效果,获得了限幅效果较好的悬浮液参数。
[Abstract]:With the rapid development of laser weapon technology, the requirements of laser protection technology are also increasing, which greatly promotes the development and progress of laser protection technology.At present, using optical limiting technology based on nonlinear optical principle to realize laser protection is one of the most studied and promising technical approaches, which plays an important role in the field of high-strength laser protection.The protection technology based on the nonlinear light scattering effect of carbon nanoparticles suspension is one of the protective methods.In this paper, the optical limiting process of carbon nanotubes and carbon nanoparticles was numerically simulated based on the heat conduction theory and the equivalent sphere scattering theory, and the thickness and concentration of the suspensions were studied, taking the water and ethanol suspensions of carbon nanotubes and carbon nanoparticles as the research objects.The effects of solvent types and incident light wavelength on the limiting performance are verified by experiments, and the nonlinear optical limiting principle is analyzed. In order to obtain a stable suspension,The dispersion of carbon nanotubes in water was studied experimentally.The main contents and results of this thesis are as follows: 1.Numerical simulation of optical limiting performance of carbon nanoparticles suspension.In the optical limiting process, the formation, scattering phase, scattering coefficient and transmittance of microbubbles in suspension are numerically simulated based on heat conduction equation and meter scattering theory.The effects of solvent type and incident light wavelength on the limiting performance of the suspension were numerically simulated. The relationship between the limiting characteristics of the suspension and these factors was obtained, which provides guidance for further experiments.The dispersion properties of carbon nanotubes in aqueous media were studied.The effects of ultrasonic time, type of dispersant, concentration of dispersant and pH value on the dispersion properties of carbon nanotubes in aqueous medium were studied by using single factor experiment and orthogonal experiment.The optimal dispersion parameters were obtained, and the stable suspension with good dispersion effect was prepared, which laid a foundation for the experimental study of the optical limiting effect.The optical limiting properties of water and ethanol suspensions of carbon nanotubes and carbon nanoparticles were studied experimentally. The thickness, concentration, wall thickness, particle types, solvent types of the suspensions were analyzed.The influence of incident wavelength and repetition frequency on the optical limiting performance.At the same thickness, the limiting effect of carbon nanoparticles and carbon nanotube suspensions with the same concentration and different concentration were studied experimentally.The limiting effect of suspension was described by the transmittance, and the better suspension parameters were obtained.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.11;TB383.1

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