Large omnidirectional band gaps and selective transmission in one-dimensional multilayer photonic structures

摘要

It has been shown that a one-dimensional periodic structure such as a superlattice can exhibit the property of omnidirectional reflection, which means that any incident wave launched from the vacuum (or from a substrate) will undergo a total reflection at the superlattice boundary, whatever the incident angle or the polarization of light is. In this communication, we show that large omnidirectional band gaps can be obtained by associating two or several superlattices in tandem. We discuss the existence conditions for these gaps as compared to the usual case of a binary superlattice. By introducing a defect layer in the finite layered structure, one can obtain localized modes inside these omnidirectional band gaps, giving rise to the selective transmission through the structure. These modes appear as peaks in the transmission spectrum with a very high quality factor, and therefore may have useful applications in the frame of photonic band-gap materials.