Wikipedia
Physical optics
In physics, physical optics, or wave optics, is the branch of optics which studies interference, diffraction, polarization, and other phenomena for which the ray approximation of geometric optics is not valid. This usage tends not to include effects such as quantum noise in optical communication, which is studied in the sub-branch of coherence theory.
Usage examples of "physical optics".
At the time I will confess that I thought chiefly of the Philosophical Transactions and my own seventeen papers upon physical optics.