Unidirectional band gaps in uniformly magnetized two-dimensional magnetophotonic crystals (original) (raw)
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Two-dimensional magnetophotonic crystal: Exactly solvable model
Physical Review B, 2005
We present an analytical treatment of a two-dimensional ͑2D͒ magnetophotonic crystal ͑MPC͒ with a square lattice constructed from two infinite arrays of magnetoactive dielectric sheets at right angles, in the limit of very small sheet thickness and very high dielectric constant. Alteration of band structure by an external magnetic field is studied. Two different geometries are examined: the Faraday geometry-magnetic field parallel to the plane of 2D MPC-and the Voigt ͑Cotton-Mutton͒ geometry-magnetic field orthogonal to the plane of 2D MPC. In the case of Faraday geometry, we show that the optical activity reduces the symmetry of the system and removes degeneracy in the photonic band structure. Also, despite the weakness of magnetooptic activity, the dispersion ͑k͒ near band edges is strongly sensitive to external magnetic influence. In the vicinity of degeneracy, electromagnetic modes exhibit bistable behavior and discontinuously change their dispersion ͑k͒ when external magnetic field is applied. In the Voigt geometry s and p polarizations remain independent of each other, and only the band structure for s-polarized light is insignificantly altered.
Solvable Model of Two-Dimensional Magnetophotonic Crystal
MRS Proceedings, 2004
ABSTRACTWe present theoretical investigation of two-dimensional (2D) magnetophotonic crystal (MPC) with square lattice constructed from two infinite arrays of magnetoactive dielectric sheets at right angle, in the limit of very small sheet thickness and very high dielectric constant, such that their product is constant. Alteration of band structure by external magnetic field is studied. We show that optical activity reduces symmetry of the system and removes degeneracy in the photonic band structure. Also, despite of natural weakness of the magnetooptic activity, dispersion near band edges is found to be strongly sensitive to external magnetic influence.
Journal of Physics D: Applied Physics, 2006
When the constitutive materials of photonic crystals (PCs) are magnetic, or even only a defect introduced in PCs is magnetic, the resultant PCs exhibit very unique optical and magneto-optical properties. The strong photon confinement in the vicinity of magnetic defects results in large enhancement in linear and nonlinear magneto-optical responses of the media. Novel functions, such as band Faraday effect, magnetic super-prism effect and non-reciprocal or magnetically controllable photonic band structure, are predicted to occur theoretically. All the unique features of the media arise from the existence of magnetization in media, and hence they are called magnetophotonic crystals providing the spin-dependent nature in PCs.
Journal of the Optical Society of America B, 2007
An analytical formulation for the band structure and Bloch modes in elliptically birefringent magnetophotonic crystals is presented. The model incorporates both the effects of gyrotropy and linear birefringence generally present in magneto-optic thin-film devices. Full analytical expressions are obtained for the dispersion relation and Bloch modes in a layered-stack photonic crystal, and their properties are analyzed. It is shown that other models recently discussed in the literature are contained as special limiting cases of the formulation presented herein.
Magneto-optical activity of a one-dimensional photonic crystal with a magnetic defect
Physics of the Solid State, 2012
The influence of a magnetic defect on the field distribution and magneto optical properties of a one dimensional photonic crystal has been investigated. It has been shown that the maximum localization of the wave field in the defect layer is achieved in an asymmetric photonic crystal structure. A greater Faraday rotation, which significantly exceeds the angle of rotation of the polarization plane in an isolated magnetized layer, and a higher degree of localization of the wave field can be achieved when the magnetic layer is sur rounded by layers of photonic crystal mirrors with a lower refractive index. An increase in the Faraday rotation angle is determined not only by an increase in the thickness of the magnetic defect but also by a symmetric increase in the number of periods in the photonic crystal mirrors.
2D Magnetic Photonic Crystals with Square Lattice-Group Theoretical Standpoint
Progress In Electromagnetics Research, 2006
We consider possible magnetic symmetries of twodimensional square lattices with circular ferrite rods magnetized by a uniform dc magnetic field. These structures can be used as tunable and nonreciprocal photonic crystals. Classification of eigenmodes in such crystals is defined on the basis of magnetic group theory and the theory of (co)representations. Some general electromagnetic properties of the magnetic crystals such as change in the basic domain of the Brillouin zone, change of symmetry in limiting cases, bidirectionality and nonreciprocity, symmetry relations for the waves and lifting of eigenwave degeneracies by dc magnetic field are also discussed.
Effect of oblique light incidence on magnetooptical properties of one-dimensional photonic crystals
IEEE Transactions on Magnetics, 2000
We have investigated the magnetooptical properties of one-dimensional magnetic photonic crystals for the case of oblique light incidence. We developed a theoretical model based on the transfer matrix approach. We found several new effects such as transmittance resonance peak shift versus external magnetic field and the Faraday effect dependence on the incidence angle. We discuss several possible one-dimensional magnetic photonic crystals applications for the optical devices.
Magnetooptical properties of two dimensional photonic crystals
The European Physical Journal B - Condensed Matter, 2004
Magnetooptical properties of the materials with periodically modulated dielectric constantphotonic crystals (or band-gap materials) have been examined with relation to their possible applications for the control of electromagnetic radiation in the integrated optics devices. For this investigation we propose the original theoretical approach based on the perturbation theory. Magnetooptical Faraday and Voigt effects have been studied near extremum points of photonic bands where their significant enhancement takes place. On the grounds of the elaborated theory some experimental results are discussed. Experimentally obtained Faraday rotation angle frequency dependence shows good agreement with our theoretical predictions.
Physical Review B, 2011
This study examines photonic stop band reconfiguration upon magnetization reversal in multimode elliptically birefringent Bragg filter waveguides. Magnetization reversal in longitudinally magnetized magneto-optic waveguides affects the character of the local orthogonal elliptically polarized normal modes, impacting the filter's stop band configuration. Unlike the standard case of circular birefringence in magneto-optic media, opposite helicity states do not transform into each other upon magnetization reversal for a given propagation direction. Rather, helicity reversals yield new and different normal modes with perpendicularly oriented semimajor axes, corresponding to a north-south mirror reflection through the equatorial plane of the Poincaré sphere. For asymmetric contradirectional coupling between different-order waveguide modes in multimode magnetophotonic crystals, this symmetry breaking, namely, the obliteration of normal modes upon magnetization reversal, allows for strongly reconfigured stop bands, through the hybridization of the elliptically polarized states. The effect of Bloch mode reconfiguration on the stop band spectral profile contributes to the magnetic response of the filter. In such elliptically birefringent media, input polarization helicity reversal also becomes a powerful tool for optical transmittance control. Both magnetization and helicity reversals can thus serve as useful tools for the fabrication of on-chip magnetophotonic crystal switches.
Physical Review B, 2009
Interleaving magnetophotonic garnet layers with layers of a structurally chiral material ͑SCM͒ leads to a one-dimensional helicoidal magnetophotonic crystal, the interaction of whose overall period and the helicoidal period of the SCM layers leads to intra-Brillouin-zone photonic band gaps which depend on the structural handedness of the SCM layers and whose gap widths are magnetically controllable. Even as the overall period grows very large, one photonic band gap remains unaffected as it is due to the helicoidal period. Also, the gap widths can be magnetically decreased by turning up the magnitude of the externally impressed dc magnetic field.