Orbital Angular Momentum

Measuring orbital angular momentum superpositions of light by mode transformation (2011) by Gregorius C. G. Berkhout, Martin P. J. Lavery, Miles J. Padgett, and Marco W. Beijersbergen

Direct measurement of the skew angle of the Poynting vector in a helically phased beam (2006) by Jonathan Leach, Stephen Keen, Miles J. Padgett, Christopher Saunter, and Gordon D. Love

Angular momentum of a rotating light beam (2005) A.Ya. Bekshaev, M.S. Soskin, M.V. Vasnetsov