Spontaneous emission plays a fundamental role in all radiative processes. It limits the lifetime of excited atoms, causing basic uncertainty in their energies. It sets the scale for absorption and stimulated emission, providing a natural scale for the coupling of matter and radiation. It is the ultimate source of noise in nature. Spontaneous emission is such a ubiquitous process that its occurrence is generally taken for granted. In principle, however, spontaneous emission can be altered, either enhanced or inhibited, allowing one to modify primary radiative processes. Experimental techniques are available for realizing these possibilities, and a new area of radiative phenomena is opening for study.
© 1982 Optical Society of AmericaPDF Article