# Orbital angular momentum coupling in elastic photon-photon scattering

## TL;DR

This paper explores how orbital angular momentum influences elastic photon-photon scattering in vacuum, proposing a new experimental approach to detect OAM signatures in generated photons using high-power lasers.

## Contribution

It introduces exact solutions carrying OAM to the vacuum electromagnetic wave equation and derives the coupling effects within an effective field theory framework.

## Key findings

- OAM affects the coupling between initial photon waves
- OAM introduces a detectable signature in generated photons
- Proposes a laser experiment to observe OAM effects

## Abstract

In this letter, we investigate the effect of orbital angular momentum (OAM) on elastic photon-photon scattering in vacuum for the first time. We define exact solutions to the vacuum electro-magnetic wave equation which carry OAM. Using those, the expected coupling between three initialwaves is derived in the framework of an effective field theory based on the Euler-Heisenberg La-grangian and shows that OAM adds a signature to the generated photons thereby greatly improvingthe signal-to-noise ratio. This forms the basis for a proposed high-power laser experiment utilizingquantum optics techniques to filter the generated photons based on their OAM state