arXiv:2111.08402 · AVS Quantum Science

Imaging inspired characterization of single photons carrying orbital angular momentum

Vimlesh Kumar, Varun Sharma, Sandeep Singh, Suddapalli Chaitanya Kumar, Andrew Forbes, M. Ebrahimzadeh, G. K. Samanta

Published Feb 11, 2022• 8 citations

Abstract

We 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.

DOI: 10.1116/5.0078870

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