Informationally complete orbital angular momentum tomography with intensity measurements

We will present the tomography of the spatial structure of light with a simple technique that allows one to perform 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, and this is experimentally verified in both the intense and photocount regimes. Our method can be useful for both classical and quantum information protocols.