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. Laser light does not need to be visible. NIF beams start out as. In today's tutorial, we will explain What is Laser Diode. Amplification of light by stimulated photon emission produces a monochromatic, directional, coherent, and high-intensity beam.