Laser-material interaction is the physical process by which a focused, coherent, monochromatic light beam exchanges energy with a solid or liquid target through absorption, conversion into heat, and subsequent phase and structural change in the irradiated region ^[1] The interaction begins when photons are absorbed by the electronic or vibrational states of the material; the absorbed energy is then rapidly converted into lattice heat, producing localized heating whose magnitude depends on the laser wavelength, pulse duration, power density, and optical absorptivity of the material. At low fluences the result is heating and annealing; at intermediate fluences the surface melts and resolidifies; at high fluences the material evaporates, ablates, or forms a plasma above the surface. Because the energy is deposited in a very shallow, sharply localized volume, the process produces steep thermal gradients and rapid cooling that govern melting depth, evaporation rate, resolidification microstructure, and the formation of induced stress or shock waves ^[2]. The field is therefore defined as the coupling between electromagnetic radiation and matter that drives localized absorption, thermal transport, melting, vaporization, and ablation, forming the physical basis of materials processing by directed laser energy ^[3].