Abstract

We describe an approach to determining both the angular and the radial modal content of a scalar optical beam in terms of optical angular momentum modes. A modified Mach–Zehnder interferometer that incorporates a spatial rotator to determine the angular modes and an optical realization of the fractional Hankel transform (fHT) to determine the radial modes is analyzed. Varying the rotation angle and the order of the fHT produces a two-dimensional (2D) interferogram from which we extract the modal coefficients by simple 2D Fourier analysis.

© 2011 Optical Society of America

Radial mode dependence of optical beam shifts

N. Hermosa, Andrea Aiello, and J. P. Woerdman
Opt. Lett. 37(6) 1044-1046 (2012)

Measurement of the orbital angular momentum spectrum of partially coherent beams

H. Di Lorenzo Pires, J. Woudenberg, and M. P. van Exter
Opt. Lett. 35(6) 889-891 (2010)

Efficient separating orbital angular momentum mode with radial varying phase

Cheng Li and Shengmei Zhao
Photon. Res. 5(4) 267-270 (2017)

Measuring orbital angular momentum superpositions of light by mode transformation

Gregorius C. G. Berkhout, Martin P. J. Lavery, Miles J. Padgett, and Marco W. Beijersbergen
Opt. Lett. 36(10) 1863-1865 (2011)

Fiber coupler for generating orbital angular momentum modes

Yan Yan, Jian Wang, Lin Zhang, Jeng-Yuan Yang, Irfan M. Fazal, Nisar Ahmed, Bishara Shamee, Alan E. Willner, Kevin Birnbaum, and Sam Dolinar
Opt. Lett. 36(21) 4269-4271 (2011)