A quantum description of the beam splitter
Alfredo Luis, Luis Lorenzo Sánchez-Soto · Quantum and Semiclassical Optics Journal of the European Optical Society Part B · 1995
The unitary operator representing the action of a linear lossless passive beam splitter is presented. The derivation is based on an elementary group-theoretical approach that allows us to understand this action in terms of the Stokes operators for the incident beam. This operator is used to illustrate with some examples the coupling of noise in the beam splitter.