超光滑光学基片表面激光清洗机理与技术

分析了激光清洗技术在清洗超光滑光学在片表面应用中的难点和可行性，并利用Nd:YAG脉冲激光器对超光滑光学玻璃表面进行了激光清洗实验，实验结果表明了激光清洗技术清洗超光滑光学基片方面非常有效。在此基础上建立了激光清洗的热学模型，结合气泡成长动力学和流体力学理论，分析了超光滑光学基片表面激光清洗的机理，量化了作用了杂质微粒上的去除力。

On Efficiently Removing Micron and Submicron Particles from Super-Smooth Optical Substrate in P.R.China

Abstract: This research forms a part of an already completed project supported by NNSFC (National Natural Science Foundation of China). That quality of super-smooth optical substrate in P. R. China has not reached that of the world is mainly due to inefficient removal of micron and submicron particles from substrate. We propose using laser-cleaning techniques, which have proved efficient in other technical fields, to make such removal efficient. Figs. 2(super-smooth optical surface before laser-cleaning) and 3 (super-smooth optical surface after laser-cleaning) show that laser-cleaning is quite efficient. Section 3 discusses in much detail the mechanism of laser-cleaning. We establish a laser-heating model, shown in Fig. 4, to explain the particle removing mechanism. We derive eq. (3) for estimating the force acting on particle to be removed. In the experiment with Nd:YAG laser, we estimate a force of about 82 nN acting on 1 um particle, which is much larger than the adhesive force between the particle and the surface. Thus, laser-cleaning the micron and submicron particles from super-smooth surface is very efficient.