Time-resolved temperature measurement and numerical simulation of superposed pulsed Nd:YAG laser irradiated silicon

摘要

Time-resolved surface temperature of single crystal silicon was measured by an infrared radiation pyrometer. The silicon sample was irradiated by two pulsed Nd:YAG lasers with pulse duration of 1ms superposed by 7ns pulses, referred to as combined pulse laser (CPL). The temperature evolution of the spot center of the sample was studied under a single millisecond (ms) laser and CPL irradiation, respectively. Then an axisymmetric numerical model was established to calculate the temperature field distribution of the silicon sample. Compared with the single ms laser irradiation, the temperature rise during CPL irradiation was higher and the process of solidification was prolonged. The results may attribute to the pre-heated ms laser and the surface damage caused by the ns laser with high power density.