Spontaneous emission is a quantum process in which an excited [[Atom|atom]] or molecule returns to a lower [[Energy Level|energy level]] by emitting a [[Photon|photon]], without any external influence. The emitted photon's energy corresponds to the difference between the two energy levels. Unlike [[Stimulated Emission|stimulated emission]], which requires an external photon to trigger the transition, spontaneous emission occurs randomly, driven by quantum vacuum fluctuations. It is fundamental to a wide range of phenomena such as fluorescence, and is ultimately responsible for most light that we see. ![[spontneous_emission.excalidraw.light.svg]] >[!read]- Further Reading >[!ref]- References