Filamentation is a phenomenon that occurs when a high-intensity laser beam propagates through a nonlinear medium such as air or glass, resulting in the formation of a self-guided beam of light known as a filament. Filaments are characterized by their narrow width, long propagation distance, and high intensity, making them useful for a variety of applications including laser machining, remote sensing, and atmospheric studies. The process of filamentation involves a complex interplay of optical nonlinearities, self-focusing, and self-phase modulation, and has been extensively studied both theoretically and experimentally.