Eur. Phys. J. D (2015) 69: 219
https://doi.org/10.1140/epjd/e2015-60320-4

Regular Article

Stopping light in an active medium

¹ College of Electronic Science and Engineering, Nanjing, University of Posts & Telecommunications, Nanjing 210046, P.R. China
² Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing 210003, P.R. China
³ College of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P.R. China

^a e-mail: jwchen69@sohu.com

Received: 31 May 2015
Received in final form: 29 July 2015
Published online: 22 September 2015

Abstract

On the basis of work done by Lorentz force and Maxwell’s equations, energy conversion relationships of electromagnetic fields in the dispersive and absorptive media are analyzed. Then new definitions of stored and lossy energy densities are proposed, respectively. Furthermore, it is predicted that light may stop steadily in an active medium when both real part of impedance and imaginary part of wave vector equal zero, which corresponds to a case that time-dependent Poynting vector shift forward and then turn backward periodically.