The influence of material parameters on the frozen modes of magnetic photonic crystals
26 Dec 2007-pp 265-269
TL;DR: In this article, the influence of various physical and geometrical parameters on the frozen modes of magnetic photonic crystals was studied using the transfer matrix method, and the influence was shown to be a function of the magnetic dispersion relation.
Abstract: Multilayered structures known as photonic crystals are object of many researches lately. Some special Photonic Crystals, containing magnetic layers and misaligned anisotropic dielectric layers, show an asymmetric dispersion relation. These structures are referred as magnetic photonic crystals (MPC). The asymmetric dispersion relation can be associated with the electromagnetic unidirectionality. A unidirectional medium "freezes" the radiation of certain frequency and direction (frozen mode), being perfectly transparent for the wave with the same frequency and the opposite direction. Using the transfer matrix method, we study the influence of various physical and geometrical parameters on the frozen modes of magnetic photonic crystals.
References
More filters
TL;DR: It is shown that by proper spatial arrangement of magnetic and dielectric components one can construct a magnetic photonic crystal with strong spectral asymmetry (nonreciprocity) omega(k-->) not equal omega(-k-->).
Abstract: We study band dispersion relations omega(k-->) of a photonic crystal with at least one of the constitutive components being a magnetically ordered material. It is shown that by proper spatial arrangement of magnetic and dielectric components one can construct a magnetic photonic crystal with strong spectral asymmetry (nonreciprocity) omega(k-->) not equal omega(-k-->). The spectral asymmetry, in turn, results in a number of interesting phenomena, in particular, one-way transparency when the magnetic photonic crystal, being perfectly transparent for a Bloch wave of frequency omega, "freezes" the radiation of the same frequency omega propagating in the opposite direction. The frozen radiation corresponds to a Bloch wave with zero group velocity partial differential omega(k)/ partial differential k=0 and, in addition, with partial differential(2)omega(k)/ partial differential k(2)=0.
349 citations
TL;DR: In this paper, the authors present some of those ideas and show that broken reciprocity can result in electromagnetic unidirectionality, when the traveling waves can only propagate in one the two opposite directions.
Abstract: Magnetization, either spontaneous or field-induced, is always associated with nonreciprocal circular birefringence which breaks the reciprocity principle and qualitatively changes electrodynamics of medium. In magnetic photonic crystals and other periodic structures involving magnetic components, broken reciprocity can result in electromagnetic unidirectionality, when the traveling waves can only propagate in one the two opposite directions. The unidirectional wave propagation can only occur if both time reversal and space inversion symmetries of the periodic structure are broken. During the last decade there have been numerous publications devoted to this kind of phenomenon. Our goal is to present some of those ideas.
153 citations
TL;DR: In this paper, the authors analyze transient electromagnetic pulse propagation in spectrally asymmetric magnetic photonic crystals MPCs with ferromagnetic losses via a late-time stable finite-difference time-domain method FDTD implemented with perfectly matched layer PML absorbing boundary conditions.
Abstract: We analyze transient electromagnetic pulse propagation in spectrally asymmetric magnetic photonic crystals MPCs with ferromagnetic losses. MPCs are dispersion-engineered materials consisting of a periodic arrangement of misaligned anisotropic dielectric and ferromagnetic layers that exhibit a stationary inflection point in the asymmetric dispersion diagram and unidirectional frozen modes. The analysis is performed via a late-time stable finite-difference time-domain method FDTD implemented with perfectly matched layer PML absorbing boundary conditions, and extended to handle simultaneously dispersive and anisotropic media. The proposed PML-FDTD algorithm is based on a D-H and B-E combined field approach that naturally decouples the FDTD update into two steps, one involving the anisotropic and dispersive constitutive material tensors and the other involving Maxwell’s equations in a complex coordinate space to incorporate the PML . For ferromagnetic layers, a fully dispersive modeling of the permeability tensor is implemented to include magnetic losses in a consistent fashion. The numerical results illustrate some striking properties of MPCs, such as wave slowdown frozen modes , amplitude increase pulse compression , and unidirectional characteristics. The numerical model is also used to investigate the sensitivity of the MPC response against excitation frequency and bandwidth , material ferromagnetic losses , and geometric layer misalignment and thickness parameter variations.
38 citations