Abstract

Not long ago Wolf discovered a modification of the spectrum of radiation due to the spatial coherence of the source.¹ His analysis used a model correlation function that demonstrated the effect, without discussing any physical mechanism by which the correlations may arise. This paper presents an analysis of one such physical mechanism, namely, the radiation reaction. Following earlier work by Varada and Agarwal,² an explicit calculation, performed in the harmonic oscillator approximation, for two radiating atoms in equilibrium with a thermal field reveals a relationship between this effect and the well-known shift of atomic oscillator frequencies due to Lamb.

© 1991 Optical Society of America