Investigation of the transient phase change of silicon irradiated by CW fiber laser

Abstract The transient phase change of continuous wave (CW) fiber laser irradiated silicon was studied by experimental measurement of the material temperature by an infrared radiation pyrometer under various laser irradiances. The real-time measurement presented many details about the transient phase change by analyzing the physical changes and the emissivity changes of silicon during the irradiation process. Three different stages divided by laser irradiances (below melting threshold, above melting threshold and above vaporization threshold) were discussed. The waveforms of temperature curves indicated more information including heating, melting, vaporization and solidification during the irradiation and cooling periods. Furthermore, the melt initiation time, melted range and the solidification duration under various laser irradiances were inferred by the experimental results combined with the damaged morphologies obtained by an optical microscope (OM).