Process analysis of boring with pulsed laser irradiation

摘要

The boring process of various materials with KrF excimer laser (200mJ/shot) was investigated by measurements of the penetration time. The parameters in this experiment were the frequency of the laser operation and the distance of the target from the laser focal point. The correlations between the penetration time and material properties such as density, thermal conductivity, coefficient of the thermal expansion, specific heat, Young's modulus and Poisson's ratio were obtained from this experiment. The penetration time was proportional to the logarithmic of the specific heat and that of the Young's modulus. Generally the target put at the focal point of the laser was penetrated most rapidly. But in the case of the quartz plate, the most rapidly penetrated point was quite in front of the laser focal point in spite of its less beam intensity.