CORRELATION-INDUCED SPECTRAL CHANGES AND ENERGY-CONSERVATION

An energy conservation law is derived for fields generated by random, statistically stationary, scalar sources of any state of coherence. It is shown that correlation-induced spectral changes are in strict agre ement with this law and that, basic to the understanding of such chang es, is a distinction that must be made between the spectrum of a sourc e and the spectrum of the field that the source generates. This distin ction, which is obviously relevant for spectroscopy, does not appear t o have been previously recognized.