One-dimensional Magnetic Photonic Crystal Research Articles

The visible region transitions measuring of one-dimensional magnetic photonic crystal with structure [formula omitted] by magnetic circular dichroism method

Magnetic circular dichroism (MCD) spectroscopy is a powerful method to investigate and characterize magnetic materials' spin and excited electronic states. This spectroscopy method, relying on measuring the absorption difference between left circularly polarized (LCP) light and right circularly polarized (RCP) light is more precise than other spectroscopic methods. It was induced in a sample by a strong magnetic field oriented parallel to light propagation. A magnetic circular dichroism measurement system was launched in this study. The measurement setup consists of a collimator xenon lamp crossing at a polarizer angle to the main modulator axis. The obtained circular polarized light passes through the sample and is finally collected by a spectrometer. The study analyzed magnetic photonic crystal positions and transition types TiO2/SiO26/Bi:YIG/TiO2/SiO26 in the range of 500 to 700 nm; three paramagnetic transitions 6A1(6S)→4T2(4G), 6A1(6S)→4T1(4G) and, 6A1g(6S)→6T2g(6G) due to crystal field transitions at 510, 550, 580, 610, and 680 nm were identified.

Externally tunable multichannel filtering applications of organic material based 1D magnetic cold-plasma photonic crystals.

In the present research work, we employed the transfer matrix method (TMM) in addition to MATLAB software to examine the transmission properties of various organic-based one-dimensional (1D) magnetic cold-plasma photonic crystals (MCPPhCs). The proposed structures were found to be made up of periodic layers of organic materials and magnetic cold-plasma (MCP) at normal incidence. An external magnetic field (B) polarized in right-hand (RH) and left-hand (LH) configurations was applied on 1D MCPPhCs. In this study, four organic materials, namely pentane, hexane, heptane, and octane, were chosen to design four 1D photonic crystals (PCs), named as PC1 (pentane-MCP), PC2 (hexane-MCP), PC3 (heptane-MCP), and PC4 (octane-MCP). Our results indicated that the central frequency of the resonant peaks of unit transmission inside the photonic band-gap (PBG) of the respective organic PCs could be tuned towards the higher or lower frequency side by applying B polarized in RH and LH configurations, respectively. We also studied the effect of the period number N to produce closely spaced N-1 transmission channels of unit transmission inside the PBG of all four organic PCs. By increasing the period number N we could increase the number of transmission channels inside the PBG as per our desire. These multiple resonant peaks of unit transmission inside PBG could be easily modulated inside the PBG to accommodate new frequencies by applying B polarized in either RH or LH configurations, respectively. Moreover, our results showed that under the RH configuration, increasing B resulted in a shifting of the resonant peak towards the higher frequency side with a reduction in its full width half maximum (FWHM), whereas the findings were the opposite in the case of increasing B under the LH configuration. These findings may be beneficial for designing externally tuneable organic chemical sensors in the microwave frequency region.

Resonant Polariton Effects in a Structure of Equidistant Layers of a Single-Phase Hyperbolic Medium with Spatial Dispersion

It has been shown in the dissipationless limit that, if a TE or TM bulk plane wave is incident from outside on a finite planar structure consisting of nonmagnetic and antiferromagnetic dielectric layers, the inclusion of the spatial dispersion of the magnet in the case of a hyperbolic antiferromagnetic medium can lead to additional resonant refractive anomalies, in particular, effects of total reflection (transmission) of a plane electromagnetic wave and the formation of discrete localized magnon-polariton states against the continuous spectrum, and, in the regime of a one-dimensional resonant magnetic photonic crystal, to the superradiance effect.

Nonspecular Effects That Occur as a Quasi-Plane Wave Passes through a Finite Photonic Crystal with an Asymmetric Polariton Spectrum

First-order nonspecular effects emerge in the plane of layers for both reflected and transmitted waves (particularly the spatial and angular Goos–Hanchen effect) for a quasi-plane of the TM (or TE) type normally incident from outside on a finite one-dimensional magnetic photonic crystal with a spectrum of normal magnetic polaritons, asymmetrical with respect to the inversion of the direction of wave propagation.

Nonreciprocal and enhancement effect of one-dimensional magnetic photonic crystal with a gain defect

The transmission properties of one-dimensional photonic crystal composed of the Gyromagnetic and gain medium are investigated. The energy loss due to the Gyromagnetic medium is compensated by adding one gain defect layer. From the analysis, it is found that both the nonreciprocal and enhancement effect are affected considerably by the incident angle, layer thickness, external magnetic field and gain coefficient. Specifically, it is demonstrated that the gain defect layer plays an important role in achieving nonreciprocal and enhancement transmission.

Properties of magnetic photonic crystals in the visible spectral region and their performance limitations

We report on the results of computer modelling and performance analysis of the optical and magneto-optical (MO) characteristics of one-dimensional magnetic photonic crystals (MPC) of several classic design types (having either a single structure defect, or a number of these), designed for applications in the visible spectral region. The calculations are performed accounting for the real levels of optical absorption achievable in existing MO materials which currently demonstrate the best MO quality (bismuth-substituted ferrite garnets). We consider Bi2Dy1Fe4Ga1O12 as the base material for use within quarter-wave thick MO layers of MPC; silica is used for the non-magnetic transparent quarter-wave layers. The achieved results can be used to clarify the nature of the differences that exist between the expected practical potential of MPCs in integrated photonics, and the actual attained experimental results. Our results show that in MPCs optimized for light intensity modulation applications, in the red spectral region (near 650nm), the achievable levels of optical transmission are limited to about 30%. This coincides spectrally with the peaks of Faraday rotation reaching their maxima at about 25°, with further transmission increases possible in the near-infrared region. Larger Faraday rotation angles are only achievable currently in structures or single film layers with reduced transmission.

Polarization properties of defect mode in one-dimensional magnetic photonic crystal

Using 4×4 transfer matrix method, we investigate the polarization properties of defect mode in magnetic photonic crystal consisting of gyrotropic material. It is found that the position of the defect mode significant depend on the polarization of the incident light and the intensity of the applied magnetic field. As the intensity of the magnetic field increases, defect modes move toward lower frequency for right-circularly polarized light or higher frequency for left-circularly polarized light. Furthermore, we also find that position of the defect modes critically depend on the thickness of magnetized medium.

One-dimensional magnetic photonic crystal structures with wide absolute bandgaps

The photonic absolute bandgaps have many potential applications in specific fields, and some methods to enlarge the absolute bandgaps, such as adjusting the material and the rotational symmetry, constituting a heterostructure have been explored. Recently, with the occurring of metamaterial, the photonic crystal based on metamaterial has also realized the wide absolute bandgaps. However, the metamaterial is an artificially structured material of which the construction is more complicated. In this paper, one-dimensional magnetic photonic crystal structure with wide absolute bandgaps is proposed, which is composed of two kinds of magnetic materials with the same refractive index and physical thickness but different wave impedances. First of all, the transmission properties of one-dimensional magnetic and non-magnetic photonic crystals with the same wave impedance ratio are studied by using transfer matrix method. It is shown that the normalized frequency bandwidth of magnetic photonic crystal, i. e. the ratio of the band of bandgap to its center, is 0.41, while the normalized frequency bandwidth of the non-magnetic photonic crystal is 0.14. From the results, we can conclude that the absolute bandgap of the above magnetic photonic crystal is wider than that of non-magnetic photonic crystal because the former bandgap is not sensitive to the incident angle nor polarization. Secondly, we adjust the wave impedance ratios of the two kinds of magnetic materials and make them respectively reach 2, 4 and 6, with the refractive index and the physical thickness kept unchanged. By analyzing their transmission properties, it is found that the normalized frequency bandwidths of the absolute bandgaps are respectively 0.47, 0.84 and 1.03, and the greater the difference between the two wave impedances, the wider the normalized frequency bandwidth is. Thirdly, we investigate the influence of the per-layer physical thickness of the magnetic material on the bandgap, with the other parameters remaining unchanged. It is shown that the center of the absolute bandgap shifts toward high frequency with the decrease of the per-layer physical thickness. Finally, a kind of heterostructure is constructed by the above two one-dimensional magnetic photonic crystals. The normalized frequency ranges of the first and the second absolute bandgap of one magnetic photonic crystal structure are respectively 1.18-2.85 and 5.37-6.85. The normalized frequency range of the absolute bandgap of the other magnetic photonic crystal is 2.37-5.68. The normalized frequency range of the absolute bandgap of the heterostructure can be enlarged to 1.18-6.85 and the corresponding normalized frequency bandwidth can reach more than 1.41. The wide absolute bandgaps can be applied to integrated optics, optical fiber communication and high-power laser systems, according to which we may design the polarization-independent and omnidirectional devices such as reflectors, optical switchers and optical filters.

Magnetic control of waveguide modes of Bragg structures

We present the study of the waveguide modes of one-dimensional magnetic photonic crystals with in-plane-magnetized layers. There is a magneto-optical effect of nonreciprocity for the TM-modes propagating along the layers perpendicularly to the magnetization. Due to the non-reciprocity the phase velocity of the modes changes with magnetization reversal. Comparison of the effect in the non-magnetic photonic crystal with additional magnetic layer on top and a magnetophotonic crystal with altering magnetic layers shows that the effect is greater in the first case due to the higher asymmetry of the claddings of the magnetic layer. This effect is important for the light modulation with external magnetic field in waveguide structures and may be used for design of novel types of the magneto-optical devices, sensors of magnetic field or biosensors.

Interface between an optically isotropic medium and a one-dimensional magnetoelectric photonic crystal as a controlled frequency-selective surface

The effect a constant external magnetic field has on the magnitude and direction of an energy flux carried by evanescent TM or TE wave in a two-component one-dimensional magnetic photonic crystal of the centroantisymmetric antiferromagnetic type (a nonmagnetic insulator) is investigated.

Free-standing, flexible thermochromic films based on one-dimensional magnetic photonic crystals

Instant radical polymerization of sterically stabilized magnetically responsive photonic crystal nonaqueous suspensions under magnetic field can obtain flexible thermochromic free-standing films, which display bright iridescent colors strongly sensitive to temperature with good reversibility and durability.

Polarization gaps in one-dimensional magnetic photonic crystal

We studied the property of magnetic photonic crystal by using the 4×4-matrix method. The transmittance cures and the corresponding band structures show that this kind of structure possesses significant polarization gaps. We find that application of an external static magnetic field causes the right-hand and left-hand circularly polarized waves to become separated, the polarization gap open up while the absolute photonic band gap disappears.

General conditions of polarization-independent transmissions in one-dimensional magnetic photonic crystals

Based on the transfer matrix theory, general conditions of polarization-independent transmissions in one-dimensional photonic crystals are derived. It is shown that the polarization-independent transmissions are obtained in photonic crystals consisting of two alternating layers with the same refraction index and optical thickness as well as the mutually reciprocal wave impedance. By using two different photonic crystals satisfying the above relation to constitute the light quantum-well structures, the structures have polarization-independent transmission properties. When a defective layer with wave impedance of 1 is introduced in the photonic crystals, the defective photonic crystals also have the polarization-independent transmission properties. In addition, polarization-independent low-pass spatial filters are achieved based on these photonic crystal structures.

Tunable double-channel filter based on defect mode splitting of one-dimensional magnetic photonic crystal

Based on a one-dimensional magnetic photonic crystal made of magneto-optic material, a tunable double-channel filter is presented. The tunability of such a filter can be achieved by defect mode splitting in the presence of external magnetic fields. Using the 4×4 transfer matrix method, the influences of the structural and compositional parameters are also analyzed, such as the magneto-optical effect, number of layers and angle of incidence.

Electric Field Controlled Optical and Magneto-Optical Effects at Light Transmission Through a One-Dimensional Magnetic Photonic Structure with Complex Defect Layer

One-dimensional magnetic photonic crystal with electro-optic and magneto-optic defect layers has been studied. The influence of the defect layers position inside a photonic crystal, as well as an action of a DC external electric field on the transmittivity spectra and Faraday rotation is investigated theoretically, taking into account the frequency dispersion of the system permittivities.

Splitting of defect-mode in one-dimensional magnetic photonic crystal

Using the 4×4 transfer matrix method, we investigate the splitting of defect-modes in one-dimensional magnetic photonic crystal. Numerical results exhibit defect-mode splitting in the presence of external magnetic fields. The splitting condition has been examined. The results show that defect-mode splitting critically depends on the magneto-optical gyrotropy factor and number of layers. We predict theoretically that magnetic photonic crystal consisting of gyrotropic material can be used as a tunable filter.

Far infrared Faraday rotation effect in one-dimensional microcavity type magnetic photonic crystals

The far infrared transmittances and Faraday rotation effect in one-dimensional photonic crystals that contain magnetic microcavities are calculated with the transfer matrix method. The different stacking sequences of dielectric layers in the magnetic photonic crystal are considered in this paper, and the linewidths of transmission peaks and localised light of the photonic crystals are discussed. The enhancement of Faraday rotation is presented in the magnetic photonic crystals, and the largest rotation angle at the frequency of the transmission peak is 29 °mm −1, which is larger than previous results.

Analysis of enlargement of the omnidirectional total reflection band in a special kind of photonic crystal based on the incident angle domain

A special kind of one-dimensional (1D) magnetic photonic crystal (MPC) is investigated. The refractive indices of the alternating layers in such a MPC are equal. As a result, the stop-band edges of TE mode coincide with those of TM mode, and the stop-bands for both modes expand as the incident angle increases. Based on the incident angle domain method, the omnidirectional total reflection (ODTR) band determined by the wave impedance ratio between the composites can be enlarged substantially using a heterostructure in which the stop-band edges of the sub-PCs can be completely adjacent at any incident angle. Moreover, the requirement of ODTR of each sub-PC is unnecessary, which extends the range of materials; that is, the wave impedance ratio between the composites and the refractive index ratio between the composites and the incident media can be much lower than that required in a single periodic structure.

Anomalies in the polariton dynamics of a one-dimensional magnetic photonic crystal with antiferromagnetic interlayer ordering in an external DC electric field

The effect of an external dc electric field on the electrodynamic properties of a one-dimensional magnetic photonic crystal (MPC) with antiferromagnetic interlayer ordering is analyzed within the effective-medium method with regard to the quadratic magneto-optical interaction. The magnetizations of adjacent tangentially magnetized ferromagnetic layers are antiparallel. In particular, the effect of a magnetic compensation point on the character of polariton dynamics in this type of MPCs is revealed.

Polariton dynamics of a one-dimensional gyrotropic magnetic photonic crystal in a dc electric field: II. Surface waves

Localization and dispersion of collective magnetic TE and TM polaritons are analyzed for a semi-infinite, one-dimensional, magnetic photonic crystal of the compensated antiferromagnetic-nonmagnetic dielectric type in the presence of orthogonal magnetic and electric fields. The case where easy magnetization axis is orthogonal to the external electric field is considered.