Generation of surface polaritons in dielectric cylindrical waveguides

A S Kotanjyan,A R Mkrtchyan,V Kh Kotanjyan,A A Saharian

doi:10.1103/physrevaccelbeams.22.040701

Abstract

We investigate the radiation of surface polaritons by a charged particle rotating around a dielectric waveguide. The general case is considered when the waveguide is immersed in a homogeneous medium. For the evaluation of the corresponding electromagnetic fields the electromagnetic Green tensor is used. A formula is derived for the spectral distribution of the radiation intensity for surface-type modes. It is shown that the corresponding waves are radiated on the eigenmodes of the dielectric cylinder. We demonstrate that the number of radiated quanta for surface polaritons of a given harmonic can be essentially larger than that for guiding modes of the cylinder. The geometry under consideration is of interest from the point of view of generation and transmitting of waves in waveguides, a subject which is of considerable practical importance in microwave engineering and optical fiber communications.

Highlights

The interfaces between two media with different electromagnetic characteristics give arise to the existence of new types of electromagnetic modes
The geometry under consideration is of interest from the point of view of generation and transmitting of waves in waveguides, a subject which is of considerable practical importance in microwave engineering and optical fiber communications
SPPs are evanescent electromagnetic waves propagating along a metal-dielectric interface as a result of collective oscillations of electron subsystem coupled to electromagnetic field

Summary

INTRODUCTION

The interfaces between two media with different electromagnetic characteristics give arise to the existence of new types of electromagnetic modes. SPPs are evanescent electromagnetic waves propagating along a metal-dielectric interface as a result of collective oscillations of electron subsystem coupled to electromagnetic field. They exist in frequency ranges where the real part of the permittivity undergoes a change of the sign at the interface. [11,12] It was shown both analytically and numerically that if the Cherenkov condition for permittivity of the cylinder and for the velocity of the particle image on the cylinder surface is obeyed strong narrow peaks appear in the angular distribution of the radiation intensity on a given harmonic.

ELECTRIC FIELD OUTSIDE THE CYLINDER

RADIATION FIELDS FOR SURFACE-TYPE MODES

For n function

RADIATION INTENSITY

SUMMARY