Coupling of impurity modes in one-dimensional periodic systems - art. no. 016604

One-dimensional periodic dielectric structures are known to exhibit band ga ps because of their symmetry. Defect states can be found in the band gaps i f an impurity layer is added to the lattice such that the symmetry of the s tructure is broken. In this paper, we consider the case where a second impu rity layer is added and we discuss the existence of coupling between the tw o defects. We discuss the possibility of exploiting the coupling of impurit y modes in the realization of tunable wavelength emitting devices and dual- wavelength vertical-cavity surface-emitting lasers.