In this work we derive expressions for the orbital angular momentum (OAM) density of light, for both symmetric and nonsymmetric optical fields, that allow a direct comparison between theory and experiment. We present a simple method for measuring the OAM density in optical fields and test the approach on superimposed nondiffracting higher-order Bessel beams. The measurement technique makes use of a single spatial light modulator and a Fourier transforming lens to measure the OAM spectrum of the optical field. Quantitative values for the OAM density as a function of the radial position in the optical field are obtained for both symmetric and nonsymmetric superpositions, illustrating good agreement with the theoretical prediction.
Reference:
Dudley, A.L., Litvin, IA and Forbes, A. 2012. Quantitative measurement of the orbital angular momentum density of light. Applied Optics, vol. 51(7), pp 823-833
Dudley, A. L., Litvin, I., & Forbes, A. (2012). Quantitative measurement of the orbital angular momentum density of light. http://hdl.handle.net/10204/6111
Dudley, Angela L, IA Litvin, and A Forbes "Quantitative measurement of the orbital angular momentum density of light." (2012) http://hdl.handle.net/10204/6111
Dudley AL, Litvin I, Forbes A. Quantitative measurement of the orbital angular momentum density of light. 2012; http://hdl.handle.net/10204/6111.
Copyright: 2012 OSA. This paper was published in Applied Optics and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/ao/submit/review/copyright_permissions.cfm. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.
