A laser diode is a semiconductor device that emits coherent and monochromatic light through the process of stimulated emission. It works by applying a forward bias to a p-n junction, causing electrons and holes to recombine in the active region and produce photons. These devices are capable of producing an intense laser ray with uniformly sized light waves. Unlike conventional light-emitting diodes (LEDs), which produce broad-spectrum, incoherent light, the laser diode generates an intense beam at a single. Laser diodes represent one of the most significant technological achievements in modern photonics, transforming electrical energy directly into coherent light through semiconductor physics. As a light source with excellent directivity and rectilinear propagation that enables easy control of energy, laser diodes are used.