Superluminal pulse reflection in asymmetric one-dimensional photonic band gaps - art. no. 037601

Superluminal pulse reflection is shown to occur in a class of one-dimension al asymmetric photonic band gaps in which a spectral window inside the gap is opened. By means of a coupled-mode equation analysis, we describe in det ail two possible realizations of superluminal pulse reflection that can be achieved using fiber Bragg gratings. The former method is based on the intr oduction of a defect into the otherwise periodic dielectric structure, wher eas the latter one exploits the interference of two closely-spaced resonanc e modes and simulates the dispersion properties of an inverted medium posse ssing a doublet line.