Electromagnetic radiation in a time-varying background medium

Autor: Budko, Neil V.
Rok vydání: 2009
Předmět:
Zdroj: Phys. Rev. A 80, 053817 (2009)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevA.80.053817
Popis: Analytical solutions are presented for the electromagnetic radiation by an arbitrary pulsed source into a homogeneous time-varying background medium. In the constant-impedance case an explicit radiation formula is obtained for the synchronous permittivity and permeability described by any positive function of time. As might be expected, such a medium introduces significant spectral shifts and spatio-temporal modulation, which are analized here for the linear and exponential time-variations of the medium parameters. In the varying-impedance case the solution is obtained for the fourth-order polynomial time-dependence of the permittivity. In addition to the spectral shifts and modulation this spatially homogeneous medium scatters the field introducing causal echoes at the receiver location.
Comment: 17 pages, no figures
Databáze: arXiv