【作者】 钱彦；

【导师】 陆建； 倪晓武； 沈中华；

【作者基本信息】 南京理工大学 ， 光学工程， 2004， 硕士

【摘要】 本文首先系统分析了气态、液态、固态介质中激光等离子体冲击波波前传播特性的相关理论，采用基于光束偏转法的光纤传感器分别对空气介质、水介质中的激光等离子体冲击波自由衰减时其波阵面上的有关物理参量进行了探测，并首次用这套装置探测到了透明固体有机玻璃介质中的激光等离子体冲击波。相比其它类型探测装置，该装置结构简单、调节方便、灵敏度高，不会对流场造成破坏。 结合冲击波波阵面处的动量、能量、质量守恒定律以及冲击波波阵面处的压强、密度、波后粒子运动速度等重要理论模型，通过对实验数据的处理分析，分别得到了自由衰减条件下，空气中、水中、有机玻璃中冲击波波阵面上各参量的衰减变化趋势，并讨论了入射激光能量和介质物理特性对冲击波的影响。结论表明，同种介质中，入射激光能量越大，冲击波衰减越慢；入射激光能量相同时，冲击波在波阻抗较小的空气介质中衰减最慢，而在波阻抗较大的固体有机玻璃介质中衰减得最快。 论文的实验结果与分析表明实验采用的基于光偏转法的光纤传感器可以用来测量各种透明介质中冲击波波前参量的特性。本文的结论不仅对研究激光与物质相互作用的相关理论具有重要意义，而且它还给激光武器的研究以及激光加工，激光医疗等领域提供理论和实验依据。更多还原

【Abstract】 The laser-induced plasma shock waves propagation in gas, liquid and solid are systemically investigated in theory. By means of a new method based on a fiber-coupling optical beam deflection technique, a detailed experimental study has been made to clarify the characteristics of shock waves in different media. And it is the first time that the shock waves in (C2H4)n be detected by this method. Comparison of others techniques, this equipment is simple, effective and easy to adjust.Studied the essential theory of shock waves, the temporal and spatial variation of some important parameters on the shock front are obtained by analyzing the results of experiments. And the influence of the laser energy and the media are investigated by experiment. The experimental results reveal that shock waves, in the same medium, attenuate more slowly with the increase of laser energy; and if laser energy is equivalent, shock waves in air attenuate more slowly while shock waves in (C2H4)n attenuated faster.Then by combination with other literature’s report, we get the same results. Therefore, the method based on a fiber-coupling optical beam deflection technique offers new possibility for study of the temporal and spatial development of shock front in many transparent media. Besides, these research results will provide the theoretical and experimental reference to laser processing, laser medicine and other corresponding fields.更多还原