Generation of polarization-entangled counter-propagating photons with high orbital angular momentum

TL;DR

This paper proposes a fiber-based method to generate polarization-entangled photon pairs with high orbital angular momentum modes, enabling advanced quantum information applications with robust control over photon properties.

Contribution

It introduces a novel fiber-based source of high-order OAM entangled photons using four-wave mixing and mode conversion, with a comprehensive theoretical framework and spectral control.

Findings

Successful theoretical modeling of the photon generation process

Demonstration of control over the joint spectral amplitude

Potential for robust high-order OAM entangled photon sources

Abstract

Spin and orbital angular momenta of light are attractive resources to harness for encoding, and manipulating information, with applications in various quantum photonic technologies. However, to fully harness that potential, we require robust sources of high-order angular momentum photons exhibiting nonclassical correlations. Here we propose a fiber-based source of polarization-entangled photons in high-order orbital angular momentum (OAM) modes. In our setup the pairs or photons are generated in a cylindrical fiber through a four-wave mixing process, which induces polarization, or spin entanglement. The photons are then converted to modes exhibiting large OAM by the two helical gratings inscribed in the core of the fiber. We present a complete theoretical framework used to consistently describe this process, and demonstrate a robust control over the joint spectral amplitude of the generated photons.