Orbital angular momentum and highly efficient holographic generation of nondiffractive TE and TM vector beams

摘要

This paper discusses the angular momentum to energy ratio for a class of nondiffractive vector beams. Using the Humblet decomposition, we introduce closed form equations for the orbital, the spin, and the surface angular momenta in both paraxial and nonparaxial regimes. The considered monochromatic beams are exact solution to the Maxwell equations in free space and can be either transverse electric (TE) or transverse magnetic (TM). In this context, we analytically show that the total angular momentum is purely orbital. Additionally, we address both numerically and experimentally the generation of nondiffractive vector beams. In the generation of the vector beams, we propose a general approach to encode the corresponding scalar beams into the Kinoform, which possesses the upper bound diffraction efficiency. Our approach is general in the sense that we can encode arbitrary nondiffractive TE and TM vector beams. The experimental setup consists of two stages; a 4-f system and a common path interferometer. To highlight the proposed approach, we experimentally generate high efficiency Bessel, Mathieu, and Weber vector beams. (C) 2014 Elsevier B.V. All rights reserved