Transition radiation on a dynamical periodical interface

TL;DR

This paper derives a formula for transition radiation on a periodically deformed interface between dielectric media, revealing multiple peaks in the radiation spectrum influenced by the interface's periodicity and the incidence angle.

Contribution

It introduces a new analytical formula for spectral-angular distribution of transition radiation on dynamic, periodic interfaces, including surface wave effects.

Findings

Multiple peaks appear in the radiation spectrum due to periodic interface structure.

The number and position of peaks depend on incidence angle and interface period.

Conditions for peak appearance are explicitly specified.

Abstract

We investigate the transition radiation on a periodically deformed interface between two dielectric media. Under the assumption that the dielectric permittivities of the media are close, a formula is derived for the spectral-angular distribution of the radiated energy in the general case of non-static profile function for the separating boundary. In particular, the latter includes the case of surface waves propagating along the boundary. The numerical examples are given for triangular grating and for sinusoidal profile. We show that instead of a single peak in the backward transition radiation on a flat interface, for periodic interface one has a set of peaks. The number and the locations of the peaks depend on the incidence angle of the charge and on the period of the interface. The conditions are specified for their appearance.