Informationally Complete Orbital Angular Momentum Tomography with Intensity Measurements

Abstract

In this work we study the tomography of the spatial structure of light. We develop a simple technique that allows one to perform the tomography over the space of fixed order modes. The technique is based on two spatially resolved intensity measurements, the second of which is performed after the light field has undergone an astigmatic transformation implemented by a tilted lens. We demonstrate that this method is informationally complete within the considered subspaces, which is experimentally verified both in the intense and the photocount regime. We also study the effect of obstructions in our ability to reconstruct the states. The work here presented is expected to help the development of characterization techniques in the field of structured light and in its application for both classical and quantum information protocols.