Whenever the natural modes of the modal expansion of the cross-spectral density have a common waist, the wave equation in the waist plane has the form of a two-dimensional Schrodinger equation. Thus the results of quantum mechanics and quantum statistics, including the quantized Schrodinger field, can be transferred to partially coherent light. Such conceptions as temperature, entropy, and energy are used advantageously. A subclass of radiation, radiation in thermal equilibrium, is introduced, and, as examples, the Gaussian Schellmodel beam and the quasi-rectangle model beam are investigated. The M<sup>2</sup> factor is strongly related to the mean value of energy.
© 1994 Optical Society of America
R. Gase, "Methods of quantum mechanics applied to partially coherent light beams," J. Opt. Soc. Am. A 11, 2121-2129 (1994)