TRAVERSAL TIME IN PERIODICALLY LOADED WAVE-GUIDES

We derive general expressions for the transmission coefficient and the traversal time in waveguides periodically loaded with dielectric slab s. We apply the results to resonant tunneling between two regions belo w cut-off, with exponentially decaying modes. At the resonant frequenc ies, we found a relationship between the traversal time and the lifeti me. We also study the photonic band gap in a periodic quarter waveleng th structure. As in several experiments, we found superluminal velocit ies.