开展了毫秒脉冲激光辐照单晶硅的实验研究, 基于马赫-曾德尔干涉技术测量了毫秒脉冲激光与单晶硅相互作用过程中的在线应力损伤。用COMSOL Multiphysics有限元仿真软件建立了毫秒脉冲激光辐照单晶硅的数值仿真模型。从理论和实验两方面探讨了毫秒脉冲激光与单晶硅作用时, 相同脉宽不同能量密度下应力场随时间的演变规律。进一步研究了干涉条纹的处理方法, 基于传统x轴投影法提出了用45°投影法来计算材料各方向上的应变, 并对两种处理方法得到的实验结果进行了对比。结果显示: 与仿真结果相比, x轴投影法实验结果的误差为9.5%~29.3%, 而45°投影法实验结果的误差为0.1%~22.6%, 表明用马赫-曾德尔干涉法测量激光辐照单晶硅产生的在线应力损伤时, 采用45°投影法计算材料各方向上的应变结果更为准确。该实验和计算方法为单晶硅在线应力损伤的研究提供了理论和实验上的指导。

An experiment of ms laser pulse irradiation on monocrystal silicon was performed. The real-time stress damage from the interaction between ms laser pulse with monocrystal silicon was measured by Mach-Zehnder interferometry. A digital simulation model for ms laser pulse irradiation on monocrystal silicon was established by COMSOL Multiphysics finite element method. The evolution law of a stress field with time under the same pulse width and different energy densities was explored when the monocrystal silicon was irradiated by ms laser pulse from theory and experiments. The processing method for interference fringes was researched and the 45°projection method was proposed to calculate the stress values of materials in different directions based on the traditional x axis projection method. Based on the numerical simulation results, the experimental results of the two methods were compared and analyzed. It shows that the error from the experimental results of the x axis projection method is in 9.5%—29.3% and that from the 45°projection method is in 0.1%—22.6% as compared with that of numerical simulation results. It is verified that the method of 45°projection is more accurate for the processing of interference fringes in the experiment of measuring the real-time stress damage by the Mach-Zehnder. The experimental results provide the theoretical and experimental guidance for the study of the stress damage of monocrystal silicon.