Excimer laser-induced melt-mediated crystallization of Si thin films on glass substrate has become an essential, substantial, and growing technology for realizing high-performance thin-film transistors (TFTs). The technology enables the manufacture of advanced ultra-high-resolution LCDs and OLED displays that are, for example, found in state-of-the-art smartphones. In addition to these increasingly sophisticated and value-added displays, the approach can also potentially provide a variety of high-quality Si films for 3D microelectronics, photovoltaic devices, and other large-area-electronic products. In the first chapter of this talk, the main technologies regarding to laser crystallization (excimer laser annealing, sequential lateral solidification) will be introduced including history from past to present. In the following chapter, various laser applications will be presented, including ultrafast laser processing, high power based cutting and welding. In addition, laser cladding which is known as one of the surface coating technologies will be briefly introduced for application to next-generation small modular reactor (SMR). In the last chapter, laser-induced melt-mediated phase separation and surface reconstruction of single-crystal silicon carbide will be presented. A single-pulse laser irradiation triggers melting of the silicon carbide surface, resulting in a phase separation into a disordered carbon layer with partially graphitic domains (~2.5nm) and polycrystalline silicon (~5nm). The results indicate a potential methodology for ultra-thin nanomaterial synthesis through the phase separation of a binary compound by laser-induced melting and solidification.