长脉冲激光辐照单晶硅的损伤特性研究

发布时间：2018-06-13 09:24

本文选题：长脉冲激光 + 单晶硅　；参考：《西华大学》2015年硕士论文

【摘要】：单晶硅是重要的红外系统窗口材料和探测器结构材料,随着激光对抗和激光技术的发展,对单晶硅激光损伤的研究具有重要的意义。本论文的主要工作如下：根据热传导理论和热弹性理论,假设单晶硅材料为各向同性且其热学参数在激光作用前后为常数,分析了不同激光功率密度和辐照时间的高斯长脉冲作用下单晶硅的温度场和热应力场,得到了激光辐照中心温度随时间的变化规律。单晶硅的抗压强度远远大于抗拉强度,单晶硅的损伤主要依赖于环向拉应力。研究了单晶硅在1064nm Nd:YAG激光1-on-1测试方法和1000-on-1测试方法下的损伤阈值,实验表明单晶硅在多脉冲下的激光损伤阈值比单脉冲下的低,原因是1000-on-1测试方法下单晶硅的激光损伤存在累积效应。研究了单晶硅在不同能量密度的高斯长脉冲激光作用下的损伤特性,并通过热效应和热力耦合效应对单晶硅的激光损伤机制进行了解释。采用不同脉冲个数的长脉冲激光对单晶硅进行击穿毁伤实验,得到了不同脉冲个数的击穿损伤阈值,并通过实验数据计算得到了单晶硅的多脉冲累积因子约为0.912。本文的研究结果可为激光对抗和激光防护领域提供必要的参考。
[Abstract]:Monocrystalline silicon is an important window material and detector structure material in infrared system. With the development of laser countermeasure and laser technology, it is of great significance to study the laser damage of monocrystalline silicon. The main work of this thesis is as follows: according to the thermal conduction theory and thermoelastic theory, the monocrystalline silicon material is assumed to be isotropic and its thermal parameters are constant before and after laser irradiation. The temperature field and thermal stress field of monocrystalline silicon under the action of Gao Si long pulse with different laser power density and irradiation time are analyzed. The variation of laser irradiation center temperature with time is obtained. The compressive strength of monocrystalline silicon is much greater than the tensile strength, and the damage of monocrystalline silicon mainly depends on the toroidal tensile stress. The damage threshold of monocrystalline silicon under 1064nm ND: YAG laser 1-on-1 and 1000-on-1 is studied. The experimental results show that the laser damage threshold of monocrystalline silicon is lower than that of monocrystalline silicon under single pulse. The reason is that the laser damage of monocrystalline silicon is cumulative under 1000-on-1 test. The damage characteristics of monocrystalline silicon under the action of Gao Si long pulse laser with different energy density are studied. The laser damage mechanism of monocrystalline silicon is explained by thermal effect and thermo-mechanical coupling effect. The breakdown damage threshold of monocrystalline silicon was obtained by using long pulse laser with different number of pulses, and the multi-pulse cumulant factor of monocrystalline silicon was calculated by calculating the experimental data. The results of this paper can provide necessary reference for laser countermeasure and laser protection.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304.12

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