Abstract

Conventional quantum treatments of the interaction between atoms and electromagnetic radiation lead to a fundamental conclusion that the rate of spontaneous emission from a collection of atoms into any resonant cavity or waveguide propagation mode is always exactly to the downward- only stimulated emission rate that would be produced in the same atoms by a signal energy of one extra noise photon in the same mode. Important general conclusions concerning thermal equilibrium and thermal noise, blackbody radiation density, laser amplifier noise figure, and quantum noise fluctuations in laser oscillators flow from this basic principle of the extra photon.

© 1986 Optical Society of America