On Axion's Effect on Propagation of Monochromatic Electromagnetic Wave Through Strong Magnetic Field

TL;DR

This paper explores how photon-axion mixing in strong, inhomogeneous magnetic fields affects electromagnetic wave propagation, predicting measurable beam splitting and intensity reduction in cavity experiments for axion detection.

Contribution

It provides an analytical solution for photon-axion induced beam splitting and intensity effects in inhomogeneous magnetic fields, aiding experimental detection strategies.

Findings

Beam splitting causes a measurable decrease in central light intensity.

Magnetic field modulation can isolate the axion effect from background noise.

Overall intensity drop is approximately 0.01%, detectable with precise measurements.

Abstract

A possibility of detecting the effect of photon-axion mixing in a cavity experiment is discussed. There are two photon-axion modes that acquire different indices of refraction and split in an inhomogeneous magnetic field. For a magnetic field inhomogeneous in the direction transverse to the light propagation an analytical solution is obtained both for the index of refraction and the beams' trajectories. In a cavity experiment, the beam splitting creates a bifurcation effect, which results in a decrease of the light intensity in the central region. Modulation of magnetic field can separate this effect from background by providing a narrow frequency range for any observed signal. When one integrates this effect over time and accounts for bandwidth, the overall drop in FWHM intensity is of order 10-2%. This is a very measurable effect.