One-dimensional Magnetic Photonic Crystal Research Articles

Polariton dynamics of a one-dimensional gyrotropic magnetic photonic crystal in a dc electric field: I. Peculiarities of refraction

It is shown that both TE and TM waves incident on the surface of a semi-infinite one-dimensional thin-layer gyrotropic magnetic photonic crystal of the magnetic-nonmagnetic dielectric type can experience a number of refraction anomalies in an external electric field due to the effect of hybridization of evanescent waves in magnetic and nonmagnetic layers. These anomalies are absent under the same conditions in spatially homogeneous media consisting of the same materials as the photonic crystal.

Design of broad omnidirectional total reflectors based on one-dimensional dielectric and magnetic photonic crystals

Omnidirectional total reflectors based on one-dimensional dielectric and magnetic photonic crystals are investigated in this paper. We adopt the transmission matrix method to analyze the transmission properties of such reflectors and use the decimal genetic algorithm to obtain broad omnidirectional total reflection (ODTR) bandwidth. Finally, an omnidirectional total reflector with very broad ODTR bandwidth of 1.34 ω 0 is achieved.

Study of Defect Modes in Photonic Band Structure of Magnetic Photonic Crystals by Means of Green's Function

In this paper, we create an analytical model to investigate the localized defect modes associated with a defect cell inserted into a one-dimensional magnetic photonic crystal. The structure is a magnetic superlattice with alternative layers of two difierent magnetic permeability containing a defect cell which is a layer of difierent nature (material or/and size) from the other layers. This leads to appearance of several localized defect modes within the magnetic photonic band gap. Our analytical approach is based on the transfer matrix and Green’s function methods to calculate the frequency and number of the defect modes which can be controlled easily by varying parameter values of the constituent layers of the magnetic photonic crystal. This method results in an analytical formula for prediction of frequency of the defect modes for both TE and TM polarizations at arbitrary angle of incidence.

Investigation of Photonic Band Gaps of One-Dimensional Heterostructure Magnetic Photonic Crystals

Multiple structures in one-dimensional photonic crystals have great potentials for ultrawide omnireflectors and tunable switches. In this paper, we study the propagation of electromagnetic waves in a one-dimensional heterostructure magnetic photonic crystal for both TE and TM incidence polarizations by means of the transfer matrix method. Results show that by stacking two magnetic photonic crystals as a heterostructure magnetic photonic crystal the omnidirectional total reflection frequency range for any polarization enlarged due to overlapping of photonic band gaps of both magnetic photonic crystals. Omnidirectional band gaps in the heterostructure magnetic photonic crystal is enhanced rather than that in a single magnetic photonic crystal.

Polariton dynamics of one-dimensional gyrotropic magnetic photonic crystal in an external dc electric field. Effective medium approach

For the example of a semi-infinite thin-layer one-dimensional gyrotropic magnetic photonic crystal of the weak ferromagnet-nonmagnetic insulator type in an external electric field, we determine the conditions under which the quadratic magnetooptic interaction will lead to various anomalies in the reflection and localization of TM or TE waves incident on the surface of the photonic crystal from outside. The electric field is a uniform dc field collinear with the equilibrium antiferromagnetic vector.

Superprism effect in one-dimensional magnetic photonic crystals

So-called magnetic-superprism effect is studied consisting in an extremely large deviation of a light ray in a photonic crystal under the influence of an external magnetic field. It is demonstrated that the magnetic superprism effect is possible in one-dimensional magnetic photonic crystals.

Polariton dynamics of a one-dimensional magnetic photonic crystal in crossed magnetic and electric fields

By an example of a semibounded one-dimensional magnetic photonic crystal (MPC) of easy-axis antiferromagnet-nonmagnetic dielectric type placed in mutually orthogonal dc magnetic and electric fields, conditions are found under which the quadratic magneto-optic interaction leads to a number of anomalies in the reflection and propagation conditions for TM or TE waves incident from outside on the surface of the superlattice. It is assumed that the easy magnetic axis is collinear to the electric field.

Optical bistability in one-dimensional magnetic photonic crystal with two defect layers

One-dimensional magnetic photonic crystal with two magnetic defect layers is theoretically studied. The dependence of defect modes inside photonic band gap on the distance between defect layers is investigated. It is shown that the cubic nonlinear polarization leads to the effect of bistability on the frequencies of defect modes.

Transformation of the TE polariton spectrum of the one-dimensional magnetic photonic crystal under conditions of the quadratic electro-optic effect

A one-dimensional magnetic superlattice of the easy-axis antiferromagnet-nonmagnetic insulator type is considered in an external static electric field applied perpendicular to the easy magnetization axis. The conditions are determined under which the quadratic magneto-optical interaction leads to a number of specific features in the conditions of localization and propagation of collective magnetic s polaritons.

Photonic band structure and effect of ε and μ on the reflectivity of one-dimensional magnetic photonic crystal structure

In this paper, we study the photonic band structure and reflection properties in one-dimensional magnetic photonic crystals (MPCs). Investigation of dispersion characteristics shows that in the case of MPCs, photonic band gaps arise due to the contrast in the wave impedance, not due to the contrast in the refractive index, while contrast in the refractive index of the two layers decides the position and number of the band gaps. We also study the effect of permittivity and permeability on reflection bands, which shows that the structure that has larger values of magnetic permeability ( μ) than dielectric permittivity ( ε) have wider TM-reflection bands, whereas the structure for which ε is greater than μ has wider TE-reflection bands. But the gap to mid-gap frequency ratio for TM-reflection bands is larger than TE-reflection bands. Thus, magnetic permeability has greater impact on the reflectivity of MPCs than dielectric permittivity. Finally, the analysis of the omni-reflectance in MPCs has also been studied.

Transformation of the polariton spectrum of a one-dimensional magnetic photonic crystal in an external dc electric field

The conditions are determined for a one-dimensional magnetic superlattice composed of an easy-axis antiferromagnet and a nonmagnetic dielectric, whose axis is collinear with the easy magnetization axis, under which quadratic magneto-optical interaction in an external dc electric field leads to a number of specific features upon localization and propagation of magnetic TM and TE polaritons.

Model System for a One-Dimensional Magnetic Photonic Crystal

We fabricate and characterize one-dimensional magnetic (rather than dielectric) photonic crystals for the first time. Our model system is a one-dimensional periodic lattice of gold-wire pairs. Each pair can be viewed as a magnetic coil with two slits and represents a "magnetic atom." Strong coupling between the resulting magnetic-dipole resonance and the Bragg resonance is accomplished by an adjacent dielectric slab waveguide, giving rise to an avoided crossing at near-infrared wavelengths. Our experimental findings are in excellent agreement with theory.

Normal modes and birefringent magnetophotonic crystals

A theoretical model for single-defect one-dimensional magnetic photonic crystals with combined linear and circular birefringences is presented. The model elucidates the polarization response of waveguide magnetophotonic crystals and predicts a spectrally asymmetric transmittance detuning from the Bragg frequency. The key components of the model are (a) the presence of two orthogonal elliptically polarized normal modes propagating at different speeds and (b) resonant transmission of these modes through the photonic crystal. Analytical expressions for the normal mode vector field amplitudes and their transmittance through the photonic crystal are obtained. The model predicts a significant nonreciprocal rotation in the presence of linear birefringence levels that would normally suppress the Faraday rotation in ordinary optical channels. Agreement is found with transfer matrix simulation predictions.

Effect of oblique light incidence on magnetooptical properties of one-dimensional photonic crystals

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.

One-dimensional bigyrotropic magnetic photonic crystals

Electromagnetic wave propagation in a one-dimensional magnetic photonic crystal (MPC) made of bigyrotropic magnetic yttrium–iron garnet and nonmagnetic gadolinium–gallium garnet is theoretically investigated using the 4×4 transfer matrix method. Band gaps in the electromagnetic spectrum are numerically obtained and appear to depend on the helicity and direction of light propagation through the MPC.

Omnidirectional reflection bands of one-dimensional magnetic photonic crystals

We study the omnidirectional reflection bands (ORBs) of one-dimensional magnetic photonic crystals. We show that the ORB is a general property of a one-dimensional magnetic photonic crystal consisting of two alternating layers with different wave impedance and the same index of refraction from the analytical expressions for the edge frequencies of omnidirectional reflection bands. We also derive the analytical expressions for equiomnidirectional contours of the omnidirectional reflection bands. These analytical expressions give the physical insights on the properties of a real finite array as well as the design parameters for device applications.

Two-dimensional Magneto-photonic Crystal Circulators

ABSTRACTPrevious research has demonstrated enhanced Faraday rotation in one-dimensional magnetic photonic crystals, where nonreciprocity in magneto-optical cavities is resonantly enhanced to provide optical isolation in optical paths on the scale of a few microns. In this paper, we study the nonreciprocity of two-dimensional magnetic photonic crystal resonators to allow further miniaturization and monolithic in-plane integration with current integrated optical devices. The nonreciprocal magnetic resonators are constructed by alternating the magnetization directions of the ferromagnetic domains in cavities side-coupled to photonic crystal waveguides. We show analytically that the gyrotropic splitting and the strength of the magnetic hybridization of the cavity modes are determined by the overlap integral between the domain magnetization vector and the modal cross product. With a large overlap obtained from optimizing the domain structures, we circularly hybridize two nearly degenerate modes to form a pair of counter-rotating whispering-gallery like modes, oscillating at different frequencies. As a physical realization, we synthesize two singly-degenerate circularly-hybridized modes in a two-dimensional crystal formed of a triangular air hole lattice in bismuth iron garnet with a TE bandgap. We tune the magnetic splitting and the decay constants of the rotating modes to demonstrate numerically a three-port optical circulator with a 30dB extinction bandwidth of 35GHz at 1550nm. An alternative implementation of a four-port circulator is achieved by side-coupling a point defect to two parallel waveguides. Our numerical experiments are performed with finite-difference time-domain simulations and agree well with the analytical coupled-mode theory predictions.