ABSTRACT
In Chapt. 10, photon wave mechanics was based on the transverse part of the vector potential. As we shall realize soon, it is quite possible to claim rightfully that other quantities constructed from electromagnetic field vectors may be considered as the photon wave function in free space. The crucial point is that whatever choice one makes for the photon wave function the subsequent photon-matter interactions must all result in the same observable consequences. In this chapter an important and interesting choice based on the Riemann-Silberstein vectors, which were introduced in Sec. 2.8, will be described.
