Kumar, VimleshVimleshKumarSharma, VarunVarunSharmaSingh, SandeepSandeepSinghKumar, S. ChaitanyaS. ChaitanyaKumarForbes, AndrewAndrewForbesEbrahim-Zadeh, M.M.Ebrahim-ZadehSamanta, G. K.G. K.Samanta2025-08-312025-08-312022-03-0110.1116/5.00788702-s2.0-85127963820https://d8.irins.org/handle/IITG2025/26170We report on an imaging-inspired measurement of orbital angular momentum (OAM) using only a simple tilted lens and an intensified charged coupled device camera, allowing us to monitor the propagation of OAM structured photons over distance, which is crucial for free-space quantum communication networks. We demonstrate the measurement of OAM orders as high as ls = 14 in a heralded single-photon source and show, for the first time, the imaged self-interference of photons carrying OAM in a modified Mach-Zehnder interferometer. The described methods reveal both the charge and order of a photon's OAM and provide a proof of concept for the interference of a single OAM photon with itself. Using these tools, we are able to study the propagation characteristics of OAM photons over a distance, which is important for estimating transport in free-space quantum links. By translating these classical tools into the quantum domain, we offer a robust and direct approach for the complete characterization of a twisted single-photon source, an important building block of a quantum network.falseArticlehttps://arxiv.org/pdf/2111.08402263902131 March 20224015001arJournal6