【作者】 孙旭光；

【导师】 欧阳秋云；

【作者基本信息】 哈尔滨工程大学 ， 光学， 2020， 硕士

【摘要】 非线性光学是现代光学的一个重要分支,它描述了光与物质的相互作用。由于激光的发明,非线性光学技术不仅可以用于基础物理研究,还可以在物理、化学、生物学和材料科学等领域进行各种应用,比如激光的产生和调制、材料分析和传感器等方面。非线性光学现象通常是在几种常见波长的激光下观察到的,并且使用了各种非线性光学材料。由于纳米制造技术的最新进展,现在可以设计出各种包含非线性成分的微纳结构材料。微纳结构材料由于其本身的小尺寸而具有电、光、磁和机械等性能,因此引起了科研人员的极大兴趣,并且微纳复合材料往往能在消除单一材料缺陷的同时具有增强的性能。由于微纳结构金属硫化物拥有独特的性能,已经被广泛应用在燃料电池、发光二极管和非易失性存储设备等领域。金属硫化物通常表现为矿物质晶体,它们丰富而廉价,为人们提供了广阔的研究前景。本文以NiCl₂、Na₂S₂O₃、Ag NO₃和Na₂S为原料,基于水热法和沉淀法,分别制备了Ni S₂、Ag₂S两种单一材料以及Ni S₂/Ag₂S复合材料。对得到的三组材料进行了微观结构表征,结果显示Ni S₂为平均直径约1.9μm、表面光滑的匀称实心球形,Ag₂S为平均尺寸150 nm左右的不均匀短棒状结构,表面分布着小突起,而Ni S₂/Ag₂S复合材料中Ag₂S颗粒团聚在Ni S₂球状粒子的表面,并且复合材料中Ni S₂和Ag₂S的数量比约为2.1:1。以PMMA为基底材料利用浇铸法制备了相应的有机玻璃,样品分散均匀且透光性良好,利用紫外-可见光谱仪分析得知（Ni S₂/Ag₂S）₉/PMMA有机玻璃表现出了最好的线性吸收性能。利用开孔Z-扫描技术测量了样品的非线性吸收性能和光限幅性能。五组PMMA有机玻璃样品均呈现反饱和吸收特性。与（Ni S₂）₉/PMMA和（Ag₂S）₉/PMMA相比,（Ni S₂/Ag₂S）₉/PMMA有机玻璃具有更好的非线性光学吸收性能。而且随着Ni S₂/Ag₂S复合材料含量的增加,其对应的有机玻璃具有更好的非线性吸收性能。同时实验数据表明,（Ni S₂/Ag₂S）₉/PMMA有机玻璃具有增强的光限幅性能。这种增强效果主要归因于Ni S₂和Ag₂S之间的协同作用,并且给出了能级跃迁角度的机制分析。在激光应用越来越广泛、材料要求越来越复杂的未来,NiS₂/Ag₂S复合材料在光开关、超快光限幅器和激光防护领域具有潜在的应用价值。更多还原

【Abstract】 Nonlinear optics is an important branch of modern optics.It describes the interaction of laser and matter.Due to the invention of laser,nonlinear optical technology can be used not only for basic physics research,but also for various applications in the fields of physics,chemistry,biology and materials science,such as laser generation and modulation,materials analysis and sensors,etc.Nonlinear optical phenomena are usually observed under lasers with several common wavelengths,and a variety of non-linear optical materials are put into application.Benefit from the latest advances in nanofabrication technology,it is now possible to design a variety of micro-nano structure materials that own nonlinear performance.Micro-nano structural materials have electrical,optical,magnetic,and mechanical properties due to their small size,which has attracted great interest from researchers,and micro-nano composite materials often have enhanced performance while eliminating single material defects.Due to the unique properties of micro-nano structured metal sulfides,they have been widely used in fuel cells,light-emitting diodes,and nonvolatile storage devices.Metal sulfides are usually expressed as mineral crystals.They are rich and cheap,and provide a broad research prospect for people.In this paper,NiCl₂,Na₂S₂O₃,AgNO₃ and Na₂S were used as raw materials.Based on the hydrothermal method and precipitation method,Ni S₂,Ag₂S and Ni S₂/Ag₂S composites were prepared respectively.The microstructure characterization of the three groups of materials showed that Ni S₂ is a smooth and uniform spherical shape with a smooth surface and an average diameter of about 1.9μm.Ag₂S is an uneven short rod-like structure with an average size of about 150 nm.Ag₂S particles in Ni S₂/Ag₂S composites agglomerate on the surface of Ni S₂ spherical particles,and the ratio of Ni S₂ to Ag₂S in the composites is about2.1:1.The PMMA was used as the base material to prepare the corresponding organic glasses.The samples were uniformly dispersed and had good light transmittance.The analysis of UV-visible spectrometer revealed that（Ni S₂/Ag₂S）₉/PMMA organic glass showed the best linear absorption performance.The nonlinear absorption performance and optical limiting performance of the samples were measured using the open Z-scan technique.All the five organic glasses exhibited reverse saturation absorption characteristics.Compared with（Ni S₂）₉/PMMA and（Ag₂S）₉/PMMA,（Ni S₂/Ag₂S）₉/PMMA organic glass has better nonlinear optical absorption performance.And as the content of Ni S₂/Ag₂S composites increases,the corresponding organic glass has better nonlinear absorption performance.At the same time,experimental data showed that（Ni S₂/Ag₂S）₉/PMMA organic glass has enhanced optical limiting performance.This enhancement effect is mainly attributed to the synergy between Ni S₂ and Ag₂S,and the mechanism analysis of the level transition is given.In the future where laser applications are becoming more widespread and material requirements are becoming more complex,Ni S₂/Ag₂S composites have potential application value in ultrafast optical limiters,optical shutters,optical switches,and laser protection.更多还原