Transit times for electromagnetic waves in metallic layered systems

Metallic multilayered arrays are considered, in the local Drude theory, to investigate transit times of electromagnetic waves and the fast response me diated by plasmon polaritons. The transit times are calculated for frequenc ies corresponding to band gaps in the dispersion relation of periodic layer ed media. At these frequencies, and depending on the thickness of the struc ture, a fast response or even a superluminal effect is predicted. This effe ct is more evident near the plasmon polariton resonances. Moreover, the tim e delay is also affected by the surface plasmon coupling between the metall ic layers. The metallic superlattices are described according to the Drude theory. (C) 2000 Published by Elsevier Science B.V. All rights reserved.