Discrete spectrum Radiation from a charged particle moving in a medium with Maxwell fish eye refraction index profile

TL;DR

This paper investigates the radiation spectrum of a charged particle in a Maxwell fish eye medium, revealing discrete spectral features, a proportional wavelength, and unique angular distribution effects due to internal reflection.

Contribution

It demonstrates the discrete nature of the radiation spectrum and the impact of lossless media on emission characteristics, including internal reflection effects.

Findings

Radiation spectrum is discrete with a main wavelength proportional to the medium's radius.

A Cherenkov-like threshold velocity is identified.

Angular distribution undergoes significant rearrangement due to internal reflection.

Abstract

Radiation from a charged particle moving in a medium with Maxwell fish eye refraction index profile is considered. It is shown that the radiation spectrum has a discrete character. The main emitted wavelength is proportional to the refractive profiles radius and has a dipole character in a regular medium. Cherenkov like threshold velocity is established. A cardinal rearrangement of angular distribution in a lossless medium is predicted. This behavior is caused by the total internal reflection in a lossless medium as opposed to photons attenuated total reflection in the regular medium. Lossless medium ensures that both directed and monochromatic emission can serve as a light source in the corresponding regions.