A Quantum Field Theory Twist to Photon Angular Momentum
arXiv:quant-ph/0509040
Abstract
A quantum field theory approach is put forward to generalize the concept of classical spatial light beams carrying orbital angular momentum to the single-photon level. This quantization framework is carried out both in the paraxial and nonparaxial regimes. Upon extension to the optical phase space, closed-form expressions are found for a photon Wigner representation describing transformations on the orbital Poincare sphere of unitarily related families of paraxial spatial modes.
10 pages, 1 figure