Magnetized Plasma Photonic Crystals Research Articles

Tunable band structure in two-dimensional magnetized plasma photonic crystal for sensing applications in terahertz frequencies

Tunable band structure in two-dimensional magnetized plasma photonic crystal for sensing applications in terahertz frequencies

Theoretical proposal of a sensor based on the comb-shaped coherent absorption realized by the magnetized plasma photonic crystals

The study presents a theoretical framework outlining a sensor capable of realizing comb-shaped coherent absorption peaks in magnetized plasma photonic crystals. The proposed model enables simultaneous measurement of alterations in the applied magnetic induction intensity, thickness of the dielectric layer, incident angle of electromagnetic waves, and the refractive index. The nascent stage of coherent absorption theory's application to photonic crystals is currently under scrutiny. Enabling interaction between both forward and backward propagating electromagnetic waves at either end of the photonic crystals creates comb-shaped absorption peaks for detecting variances in physical quantities. The sensor model utilized the transfer matrix method for computation of the transmission and reflection coefficients, linear range, sensitivity, and further linear fitting equations across all physical quantities when employed for multi-physics measurements. The present study entailed an analysis of linear range, the figure of merit, and the sensitivity of a sensor designed to detect magnetic induction intensity. Results demonstrate that the linear range from 0.7 T–1.3 T, while the figure of merit equals 50.2189 T⁻1 and sensitivity equals 4.3535 × 10⁻8 (ωd/2πc)/T. Conversely, when measuring thickness, the corresponding linear range extends from 0.4–0.85 mm, with figure of merit reaching 481.06 mm⁻1 and sensitivity equating to 3.5567 × 10⁻4 (ωd/2πc)/mm. Additionally, the sensor's application to the measurement of both incident angle and refractive index revealed parameters for linear range that ranged from 2 to 4.1, while figure of merit was calculated at 124.00 RIU⁻1 and sensitivity at 15.54952 (ωd/2πc)/RIU. Regarding incident angle, related values for linear range spanned from 15°–44°, with figure of merit established at 4.2157°⁻1 and sensitivity at 0.8661 (ωd/2πc)/degree.

A theoretical study based on coherent perfect absorption and polarization separation in one-dimensional magnetized plasma photonic crystals.

This article presents a study on tunable narrowband coherent perfect absorption (CPA), which can be altered by adjusting the initial phase to the ranges of 1.03α-1.13α (with α = 2πc/d) and 1.29α-1.43α. The relative bandwidths of these ranges are determined to be 8.5% and 7.4%, respectively. The study utilizes the transfer matrix method for calculations of the largest CPA amplitudes within one-dimensional (1D) magnetized plasma photonic crystals (MPPCs) across two absorption bands, achieving a maximum of 0.99 and 0.98, respectively. In addition, the phase modulation and amplitude modulation characteristics of the CPA are also discussed, and the results show that its absorption amplitude can be gradually modulated from 0.08 to 0.99 by the former and from 0.60 to 0.98 by the latter. The external magnetic fields have also been shown to limit the CPA amplitude between 0.41 and 0.99 within one band and between 0.52 and 0.99 within another band. The study further highlights the effect of plasma frequency and dielectric layer thickness on coherent band shifts towards high or low frequencies. Notably, the article presents the multiband polarization separation properties of 1D MPPCs, with calculated transmittance differences between the TM and TE waves of up to 0.70 and 0.74 at 1.13α and 1.37α, respectively.

Designing externally controllable optical filters with two-dimensional magnetized plasma photonic crystals

Designing externally controllable optical filters with two-dimensional magnetized plasma photonic crystals

Bandgap structure and density of states of two-dimensional magnetized plasma photonic crystals

In this paper, we study dispersion properties in a two-dimensional magnetized plasma photonic crystal, based on the modified plane wave expansion method. Transverse electric polarization is considered. The influence of different factors such as external magnetic field, lattice constant, dielectric constants of background and central rod, and electron density of plasma in photonic bandgap structure and photonic bandgap map is studied. The photonic density of states is also demonstrated. Results show that a large magnetic field produces more band gaps in higher frequencies. The lattice constant is an important factor in controlling the bandgap structure and it can compensate low magnetic field effect. Using a larger dielectric constant in the background compared to the central dielectric rod leads to more and sharper band gaps in higher frequencies. Electron density of plasma plays an important role in tuning bandgap structure. There would be three or four band areas in the band structure and the band frequencies are larger than the cutoff frequency of plasma.

Experimental study of electromagnetic wave scattering from a gyrotropic gaseous plasma column

We experimentally demonstrate the controlled scattering of incident transverse-electric electromagnetic waves from a gyrotropic magnetized plasma cylindrical discharge. Scattered electromagnetic waves can bend left and right by changing the external magnetic field of a plasma rod. Measured scattered wavefronts are in good agreement with electromagnetic simulations. A gyrotropic response is observed for incident wave frequencies ranging from 3.5 to 5.6 GHz for conditions corresponding to a ratio of cyclotron frequency to plasma frequency, ωce/ωp≈ 0.16. The observation of a gyrotropic response from cylindrical plasma discharges paves the way for their use as building blocks for future devices such as magnetized plasma photonic crystals, topological insulators, plasma metamaterials, non-reciprocal waveguide structures, and other devices, which require a tunable gyrotropic response from centimeter to meter-scale materials with application-specific geometry.

Gas sensing applications using magnetized cold plasma multilayers

In this paper, we theoretically propose a novel magnetic field-dependent sensor using omnidirectional magnetized cold plasma photonic crystal in one dimension for TE polarization. The structure consists of asymmetric two periodic arrays from magnetized cold plasma and sample cavity layer. Between the periodic arrays, a sample cavity is sandwiched between two quartz layers. The methodology of the proposed detector depends on the appearance of a sensitive defect mode. The results clear that the defect mode frequency depends significantly on the refractive index of the sample, and it is extremely sensitive to incident angle changes, applied magnetic field, the number density of electrons, and sample layer thickness. The optimized proposed sensor has high sensitivity of 15.14 GHz/RIU, quality-factor of 527.32, and figure of merit of 1066.20 RIU−1, where RIU means refractive index unit. So, the proposed sensor can aid in solving many challenges in chemical and environmental applications.

Tunable enhanced Faraday rotation in a defected plasma photonic crystal under external magnetic field with different declinations

Magneto-optical responses and the potential for tunability when changing the variables of a one-dimensional defected magnetized plasma photonic crystal have been studied using a transfer matrix method for operation in the mm-range wavelength region. The effect of the number and dielectric defect layer thickness as well as the intensity and declination angle of magnetic field on transmittance, Faraday rotation, and its ellipticity has been investigated. The results demonstrate the ability to alter the resonant modes frequency at multiple levels of precision. The structures with four, six, and eight defect layers have been investigated. The number of defect dielectric layers changes the number of resonance modes. A single defect mode appears within the photonic bandgap with four defect dielectric layers while two defect modes were observed with six layers, and three modes with eight layers. An increase in magnetic field declination decreased the Faraday rotation intensity and width of Faraday resonance mode.

Investigation on the nonreciprocal properties of one-dimensional cylindrical magnetized plasma photonic crystals.

In this paper, the equations for the transfer matrix method of one-dimensional cylindrical magnetized plasma photonic crystals are proposed, and its nonreciprocal properties based on the Thue-Morse sequence are also studied. By adding the influence of the magnetic field into Maxwell's equations in the cylindrical coordinate system, the transmission matrix equation of cylindrical wave propagation in the cylindrical medium is obtained and a quasi-periodic structure with the Thue-Morse sequence is designed to study its nonreciprocal features. By considering Maxwell's equations and the equations of motion of charged particles, the relative dielectric function of plasma under the $z$-axis magnetic field is achieved. Considering the influences of this dielectric function in the cylindrical coordinate system, the transmission matrix equations of cylindrical wave propagation in the cylindrical medium are derived, and those equations are used to design a cylindrical structure with two layers of ordinary medium and one layer of plasma satisfying the Thue-Morse sequence. It is concluded that the nonreciprocal phenomenon becomes more and more obvious with the increase of the plasma frequency, the relative dielectric constant of the medium, and the incident angle. But with the increase of ${\omega _c}$, the nonreciprocal propagation is attenuated, and there is no significant change when the collision frequency is enlarging.

Tunable Fano resonance in one-dimensional magnetized plasmon photonic crystals

In this paper, the reflection characteristics of one-dimensional (1D) magnetized plasma photonic crystals (MPPCs) are studied by using the transfer matrix method. The given structure is made up of binary photonic crystals whose unit only contains two plasma layers with different plasma frequencies and a dielectric material layer at the end. The phenomenon of Fano resonance can be realized by such a simple periodic asymmetric structure. By applying the external applied magnetic field, the properties and transmission metrics of the presented MPPCs can be achieved. The numerical results reveal that two narrow and asymmetric linear reflection peaks will appear, and a phenomenon of Fano resonance can be observed. The influences of refractive index, period constant, incident angle, and magnetized plasma parameters on the obtained Fano resonance also are investigated. The analyzed results demonstrate that the tailored Fano resonance can appear in the proposed 1D MPPCs, and the above parameters can affect its features. The stated 1D MPPCs can be used in the sensors, slow light optical devices, and so on.

Nonreciprocal absorption characteristics of one-dimensional cylindrical magnetized plasma photonic crystals

By combining the propagation matrix of planar magnetized plasma photonic crystals with that of the cylindrical non-magnetized medium, the transfer matrix equation of the cylindrical magnetized plasma photonic crystals is obtained. Applying this equation to the cylindrical structure, a quasi-periodic structure conforming to the Pell sequence is designed, which has good nonreciprocal property. Therefore, the absorptance of light propagating forward and backward in this structure are studied respectively. The concept of contrast ratio (D C ), calculated from the absorption of the forward and backward propagation of electromagnetic waves in the structure, is used to compare the degree of difference between the two. It is found that the nonreciprocal propagation becomes larger with the increase of the azimuth modulus and the relative dielectric constant of the medium, increases first, and then decreases with the increase of the incident angle, but does not change obviously when the plasma collision frequency and the cyclotron frequency of the plasma are getting larger. The absorptance decreases with the increase of azimuth modulus, relative dielectric constant, and plasma cyclotron frequency, and becomes better with the increase of the plasma collision frequency. However, when the incident angle gets larger, the absorptance becomes better at first and then gets worse.

A Space Filter Possessing Polarization Separation Characteristics Realized by 1-D Magnetized Plasma Photonic Crystals

In this article, a wide-angle space filter (SF) with absorption function based on 1-D magnetized plasma photonic crystals is proposed, which has a good rectangularity of greater than 0.95. Since the angle range (AR) of the TM polarization is larger than that of the TE, they can be split at specific angles, possessing the potential to be a polarization splitter (PS). The effects of plasma density ne and magnetic induction intensity $B$ on the AR of the SF are discussed based on the tunability of the magnetized plasma. The increase in ne shrinks the AR of TE and TM polarizations at the same time, but that of the TM decreases faster, resulting in a narrower AR of PS. If B is augmented, only the AR of the TM wave will be reduced, which will also lead to the reduction in the AR of the PS. In addition, the impedance matching theory is used to explain the cause of the generation of SF. Compared with the traditional angular filter only with the transmission function, the SF we proposed with the absorption function is relatively rare, and it may have important application possibilities in the antenna field.

A Switchable Absorption–Transmission Window Modulator Based on 1-D Magnetized Plasma Photonic Crystals

In this article, a simple periodic 1-D magnetized plasma photonic crystal (PPC) is proposed. The effects of plasma frequency and plasma cyclotron frequency on the absorption of such magnetized PPCs are investigated theoretically by the transfer matrix method. The simulated results show that, for the TM wave, a tunable absorption window in the transmission region (AWTR) can be achieved when the incident angle is 82°, and the absorption peak of AWTR shifts to the higher frequencies when the plasma frequency and plasma cyclotron frequency are increased. On this basis, a multistack structure is designed by splicing periodic PPC structures with different plasma cyclotron frequencies. The calculated results indicate that an ultrawideband absorption band can be achieved for the stacked structure, and the broadband transmission window in the absorption region (TWAR) can be obtained by changing the distribution of plasma cyclotron frequency. Besides, the ultrawideband absorption and TWAR can be realized in different frequency bands after optimization parameters. Those simulated results can provide ideas for designing the angle-dependent polarized splitters, tunable ultrawideband absorbers, radomes, or switchable absorption–transmission window signal modulators.

Multichannel filter based on tunable fibonacci quasi-periodic structure for one-dimensional magnetized ternary plasma photonic crystal

In this paper, we propose an one-dimensional magnetized plasma photonic crystal based on the ternary Fibonacci quasi-period structure, and use the transmission matrix method (TMM) to study the terahertz band comb-like multichannel filtering properties, which is different from the periodic structure multichannel properties introduced by the plasma defect or dielectric defect. Second, we give the calculation formula of the transmission matrix of the model, third, we find the numerical relationship between the number of Fibonacci sequences and the number of channels. Higher relative refractive index improves the filter performance of comb-like channels. The effect of the length of each layer on the number of channels and the frequency of adjacent comb-like channels is different from that of traditional periodic multichannel filters. The detuning of magnetic field can increase the number of filtering channels, and different incident angles have different phenomena.

Omnidirectional absorption properties of a terahertz one-dimensional ternary magnetized plasma photonic crystal based on a tunable structure

In this paper, by using the transfer matrix method and introducing the plasma as the dispersion medium, we propose the tunable one-dimensional magnetized ternary plasma photonic crystal structure (APB)N, and study its omnidirectional absorption properties of TM wave in terahertz band, where A and B are two different dielectric layers, P is plasma layer, and studied the regulation of the frequency and peak of the absorption channel by the number of periods, the relative refractive index of the dielectric layer, length, density, collision frequency and magnetic field intensity of the plasma layer to the absorption channel frequency and peak value. Therefore, this paper provides an idea for the design of terahertz absorbers for omnidirectional plasma photonic crystals.

A reconfigurable device based on the one-dimensional magnetized plasma photonic crystals nested with the Pell and Thue–Morse sequences

In this paper, the properties of a reconfigurable device which realizes the omnidirectional band gaps (OBGs), nonreciprocity (NR) and polarization beam splitting (PBS) based on the one-dimensional (1-D) magnetized plasma photonic crystals (MPPCs) nested with quasi-periodic Pell and Thue–Morse sequences are theoretically investigated by the transfer matrix method (TMM). The obtained results show that the OBGs, the NR region, and the scope of PBS can be notably manipulated by the plasma frequency, plasma cyclotron frequency, incident angle, and the plasma collision frequency. More specifically, the higher plasma frequency is needed for accomplishing the property of OBGs while the better performance of NR can be achieved with a larger incident angle and a higher plasma cyclotron frequency. Also, the lower plasma frequency and higher plasma cyclotron frequency are suitable for the splendid performance of PBS. The augment of the plasma collision frequency is adverse to the properties as mentioned above. Due to the Voigt magneto-optical effect generating from the magnetized plasma layers, the time-reversal symmetry is destroyed which is beneficial for obtaining the properties of NR and PBS. Besides, owing to the nested technology which breaks the spatial symmetry of the structure further, compared with the conventional 1-D single quasi-periodic structures, the proposed nested MPPCs have a preeminent strength in achieving the three functions through modulating the corresponding physical parameters. These findings provide theoretical guidance for the design and application of the multifunctional devices.

Analysis of the features of a multifunctional device based on the regulation of the magnetic field in one-dimensional photonic crystals containing only plasma with a novel quasi-periodic structure

In this paper, the features of a multifunctional device that are realized by one-dimensional magnetized plasma photonic crystals (MPPCs) containing only the plasma regulated by the external magnetic field in an innovative quasi-periodic arrangement are studied by the transfer matrix method, which possesses the characteristics of the omnidirectional bandgap (OBG), nonreciprocity (NR), and polarization separation (PS). The effects of the magnetic field and other physical parameters including the plasma frequency and incident angle on those three properties are illustrated, respectively. The computed results demonstrate that, with the gradually increasing magnetic field, the performances of OBG and NR apparently deteriorate while the PS region expands ideally. Meanwhile, the greater presentations of OBG and PS can be gotten with the proper rise of the plasma frequency. Nevertheless, the higher the plasma frequency is, the worse the quality of NR will be observed. Furthermore, an appropriate incident angle also plays a crucial part in the display of NR and PS for the proposed structure, and these properties can be enhanced well with a larger incident angle. This new kind of MPPC has potential application in designing tunable and multifunctional optical instruments.

Tunable multichannel terahertz filtering properties of dielectric defect layer in one-dimensional magnetized plasma photonic crystal

In this paper, the multichannel filtering properties caused by the dielectric defect layer of the one-dimensional magnetized plasma photonic crystal (PPC) in the terahertz band are studied by the transmission matrix method (TMM). The structure of (AC)N(CBC)M(AC)N is proposed, in which A is the plasma layer, B is the dielectric defect layer, C is the ordinary dielectric layer, N and M are the periods of the plasma layer and the dielectric defect layer respectively. The research shows that the filter channel generated by the structure is equal to M, and the variation of N will affect the photonic band gap (PBG) range. Secondly, the length of each layer will affect the frequency and transmission of the channel. In particular, the length of the C layer only affects the frequency of the channel and rarely affects the transmission. The refractive index of dielectric layer B affects both transmission and channel frequency. Thirdly, the increase of the plasma density causes the attenuation of the channel transmission, but rarely affects the channel frequency. The magnetic field range of PBG can be changed by controlling the plasma density. Therefore, this paper can provide ideas for the design of multi-channel tunable terahertz filter.

Tunable omnidirectional band gap and polarization splitting in one-dimensional magnetized plasma photonic crystals with a quasi-periodic topological structure

An omnidirectional band gap (OBG) can be achieved by stacked hetero-structures or conventional quasi-periodic dielectric structures, which has similar effects on both polarization waves. In this paper, a new quasi-periodic structure (QPS) is constructed to form a photonic crystal, which is composed of magnetized plasma and common dielectrics. The computed results show that different OBG features of two polarized waves can be obtained in the proposed QPS. On this basis, the polarization splitting (PS) phenomenon also can be found, and the bandwidths of both OBG and PS are ultra-wideband. The effects of plasma frequency, external magnetic field, and normal dielectrics on the performance of OBG and PS are also investigated by the transfer matrix method, respectively. It is found that the performance can be adjusted by changing those parameters. The greater OBG can be observed at a large plasma frequency and small magnetic field, while the property of PS is just the opposite. With a smaller plasma frequency or a larger magnetic field, an improved performance of PS can be obtained. These results can provide ideas for the construction of novel quasi-periodic topology, OBG devices, and polarized splitters.

Investigation on the three-dimensional magnetized plasma photonic crystals with function dielectric under magneto-optical Faraday effect

In this paper, the dispersion features of three-dimensional (3D) magnetized plasma photonic crystals with function dielectric arranged by the simple-cubic lattices which are called the function magnetized plasma photonic crystals (FMPPCs) are investigated in theory by the plane wave expansion method under the magneto-optical Faraday effect. The configuration of such FMPPCs is that the function dielectric spheres are inserted into the magnetized plasma. The relative dielectric constant of function dielectric sphere is space-depended. The parameters of FMPPCs effects on the photonic band gaps (PBGs) for the right and left circular polarization waves also are studied. The computed results demonstrate that the obtained PBGs can be tailored by those parameters as mentioned above. The larger PBGs can be achieved in the 3D FMPPCs with the spherical filler compared with those FMPPCs with the cubic filler, when their filling factors are same. The right and left circular polarization waves also can be splitted when the the parameters of FMPPCs are large enough.