Quasi-Intrinsic Angular Momentum and the Measurement of Its Spectrum

Roberta Zambrini, Stephen M. Barnett
2006 Physical Review Letters  
We introduce the concept of quasi-intrinsic angular momentum to denote fields for which the mean value of the angular momentum is unaltered by a lateral shift of the rotation axis but the spectrum changes. This property is exemplified by the orbital angular momentum of a beam of light about its propagation direction. We propose an interferometric experiment to measure efficiently the exact angular momentum spectrum and variance for light beams with any arbitrary spatial distribution.
doi:10.1103/physrevlett.96.113901 pmid:16605821 fatcat:7mltjrojmrgcrerp7uzmweutgq