Twisted Radiation by Electrons in Spiral Motion

TL;DR

This paper demonstrates that electrons in spiral motion emit twisted electromagnetic radiation with orbital angular momentum, supported by theory and experiments, and proposes new laboratory sources for such vortex photons across a wide spectrum.

Contribution

It introduces the concept of twisted radiation from free electrons in spiral motion and experimentally verifies the helical phase structure of the emitted photons.

Findings

Electrons in spiral motion emit radiation with helical phase structure.

Experimental diffraction confirms the twisted nature of the radiation.

Potential for creating vortex photon sources across various wavelengths.

Abstract

We theoretically show that a single free electron in circular/spiral motion radiates an electromagnetic wave possessing helical phase structure and carrying orbital angular momentum. We experimentally demonstrate it by double-slit diffraction on radiation from relativistic electrons in spiral motion. We show that twisted photons should be created naturally by cyclotron/synchrotron radiations or Compton scatterings in various situations in cosmic space. We propose promising laboratory vortex photon sources in various wavelengths ranging from radio wave to gamma-rays.