Spontaneous emission noise

Spontaneous emission noise occurs when atoms or molecules in a laser or light source randomly release photons without being triggered by external energy. These unpredictable photon emissions cause fluctuations in the light's intensity and phase, leading to inherent noise in the output. Essentially, it's a natural, unavoidable jitter in the light signal caused by the random timing of these atomic events, impacting the clarity and stability of laser systems and optical communication.