Статті в журналах: "Perfect transmission resonances"

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Alipourzadeh, Mohammad, Yaser Hajati, and Imam Makhfudz. "Photo- and exchange-field controlled line-type resonant peaks and enhanced spin and valley polarizations in a magnetic WSe₂ junction." Journal of Physics D: Applied Physics 55, no. 16 (January 25, 2022): 165301. http://dx.doi.org/10.1088/1361-6463/ac48ae.

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Abstract Existing resonant tunneling modes in the shape of line-type resonances can improve the transport properties of the junction. Motivated by the unique structural properties of monolayer WSe2 e.g. significant spin–orbitcoupling and large direct band gap, the transport properties of a normal/ferromagnetic/normal WSe2 junction with large incident angles in the presence of exchange field (h), off-resonance light ( Δ Ω ) and gate voltage (U) is studied. In a certain interval of U, the transmission shows a gap with optically controllable width, while outside it, the spin and valley resolved transmissions have an oscillatory behavior with respect to U. By applying Δ Ω (h), an optically (electrically) switchable perfect spin and valley polarizations at all angles of incidence have been found. For large incident angles, the transmission resonances change to spin-valley-dependent separated ideal line-type resonant peaks with respect to U, results in switchable perfect spin and valley polarizations, simultaneously. Furthermore, even in the absence of U, applying h or Δ Ω at large incident angles can give some spin-valley dependent ideal transmission peaks, making h or Δ Ω a transmission valve capable of giving a switchable fully spin-valley filtering effect. These findings suggest some alternate methods for providing high efficiency spin and valley filtering devices based on WSe2.

2

Si, Jiangnan, Shuang Liu, Weiji Yang, Xuanyi Yu, Jialin Zhang, and Xiaoxu Deng. "Broadened Angle-Insensitive Near-Perfect Absorber Based on Mie Resonances in Amorphous Silicon Metasurface." Nanomaterials 10, no. 9 (September 1, 2020): 1733. http://dx.doi.org/10.3390/nano10091733.

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A broadband near-perfect absorber is analyzed by an amorphous silicon (a-Si) hook shaped nanostructure metasurface. The transmission and reflection coefficients of the metasurface are investigated in the point electric and magnetic dipole approximation. By combining square and semicircle nanostructures, the effective polarizabilities of the a-Si metasurface calculated based on discrete dipole approximation (DDA) exhibit broadened peaks of electric dipole (ED) and magnetic dipole (MD) Mie resonances. The optical spectra of the metasurface are simulated with different periods, in which suppressed transmission are shifted spectrally to overlap with each other, leading to broadened enhanced absorption induced by interference of ED and MD Mie resonances. The angle insensitive absorption of the metasurface arrives 95% in simulation and 85% in experiment in spectral range from 564 nm to 584 nm, which provides potential applicability in nano-photonic fields of energy harvesting and energy collection.

3

Thakur, PrabhatK, and Parthapratim Biswas. "Multifractal scaling of electronic transmission resonances in perfect and imperfect Fibonacci -function potentials." Physica A: Statistical Mechanics and its Applications 265, no. 1-2 (March 1999): 1–18. http://dx.doi.org/10.1016/s0378-4371(98)00559-7.

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El-Aouni, Mimoun, Youssef Ben-Ali, Ilyass El Kadmiri, and Driss Bria. "One-Dimensional Photonic Serial Asymmetric Loops Structure Containing Three Defects." Defect and Diffusion Forum 418 (August 19, 2022): 25–37. http://dx.doi.org/10.4028/p-k1282y.

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We study in this work, the occurrence of defects modes in the transmission spectrum and the band structure of a perfect photonic asymmetric serial loops structure (ASLS) utilized for narrow-band filtering. The perfect structure presents large photonic bandgaps that result from the modes of the loops resonances and the system periodicity. Besides that, the existence of defects within this perfect ASLS, whether at the segment or loop level, or both of them, causes the appearance of two, three, or four defect modes within gaps with good transmission rates and high-quality factors. These defects modes are extremely sensitive to changes in structural parameters. This system can be used to filter or guide the incoming electromagnetic waves. The interface response theory has been used to accomplish the analytical calculation. Green's function of the full system is determinated using this method. It allows us to calculate the dispersion relation and the transmission rate. Therefore, this paper can provide ideas for the design of multi-channel tunable filter using for frequency division multiplexing and microwave and signal processing.

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Abdipour, Mahmoud, Saba Kazemi Alishahi, and Kambiz Noormohammadi. "Broadband multi-layer antenna with improved design for the applications of perfect impedance matching." International Journal of Microwave and Wireless Technologies 7, no. 6 (July 22, 2014): 747–52. http://dx.doi.org/10.1017/s175907871400097x.

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In this paper, the design of a broadband multi-layer microstrip antenna is presented. The broadband characteristics are the results of coupled resonances of the patch and transmission line through the resonant aperture. For this purpose, a cross-shaped transmission line, a ring slot, and a shaped ring patch are used. The simulation and measurement results indicate that a wide impedance bandwidth of 70% for |S11| < −10 dB and a perfect impedance matching 35% for |S11| < −20 dB are achieved. The gain is stable over the impedance bandwidth. The maximum gain of the proposed antenna is 8.8 dBi at 5 GHz. The radiation pattern, radiation efficiency, and cross-polarization are also suitable throughout the impedance bandwidth.

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Battula, Arvind, Yalin Lu, R. J. Knize, Kitt Reinhardt, and Shaochen Chen. "Extraordinary Transmission and Enhanced Emission with Metallic Gratings Having Converging-Diverging Channels." Active and Passive Electronic Components 2007 (2007): 1–8. http://dx.doi.org/10.1155/2007/24084.

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Transmission metallic gratings having the shape of converging-diverging channel (CDC) give an extra degree of freedom to exhibit enhanced transmission resonances. By varying the gap size at the throat of CDC, the spectral locations of the transmission resonance bands can be shifted close to each other and have high transmittance in a very narrow energy band. Hence, the CDC shape metallic gratings can lead to almost perfect transmittance for any desired wavelength by carefully optimizing the metallic material, gap at the throat of CDC, and grating parameters. In addition, a cavity surrounded by the CDC shaped metallic grating and a one-dimensional (1D) photonic crystal (PhC) can lead to an enhanced emission with properties similar to a laser. The large coherence length of the emission is achieved by exploiting the coherence properties of the surface waves on the gratings and PhC. The new multilayer structure can attain the spectral and directional control of emission with onlyp-polarization. The resonance condition inside the cavity is extremely sensitive to the wavelength, which would then lead to high emission in a very narrow wavelength band. Such simple 1D multilayer structure should be easy to fabricate and have applications in photonic circuits, thermophotovoltaics, and potentially in energy efficient incandescent sources.

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WAKABAYASHI, KATSUNORI, and TAKASHI AOKI. "ELECTRICAL CONDUCTANCE OF ZIGZAG NANOGRAPHITE RIBBONS WITH LOCALLY APPLIED GATE VOLTAGE." International Journal of Modern Physics B 16, no. 32 (December 20, 2002): 4897–909. http://dx.doi.org/10.1142/s0217979202014917.

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The electric conductance of the graphite ribbon with locally applied gate voltage has been studied in terms of the Landauer approach. In the low-energy region, nano-graphite ribbon with zigzag boundaries exhibits the single electronic transport channel due to the edge states. The chemical potential dependence of the electric conductance shows qualitatively different behavior, depending on whether the magnitude of the potential barrier (gate voltage bias) Vg is larger than the energy gap Δ of the single channel region of the zigzag ribbon. For positive Vg with Vg < Δ, the zero-conductance resonances appear for 0 ≤ E ≤ Vg, and average transmission probability is quite small in this region. However the transmission probability is almost one, i.e. perfect transmission, for E > Vg. This step-function-like behavior of the conductance shows that it is possible to fabricate a nano-graphite-based switching device by the application of weak gate voltage bias.

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Christensen-Dalsgaard, Jakob, Yezhong Tang, and Catherine E. Carr. "Binaural processing by the gecko auditory periphery." Journal of Neurophysiology 105, no. 5 (May 2011): 1992–2004. http://dx.doi.org/10.1152/jn.00004.2011.

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Lizards have highly directional ears, owing to strong acoustical coupling of the eardrums and almost perfect sound transmission from the contralateral ear. To investigate the neural processing of this remarkable tympanic directionality, we combined biophysical measurements of eardrum motion in the Tokay gecko with neurophysiological recordings from the auditory nerve. Laser vibrometry shows that their ear is a two-input system with approximately unity interaural transmission gain at the peak frequency (∼1.6 kHz). Median interaural delays are 260 μs, almost three times larger than predicted from gecko head size, suggesting interaural transmission may be boosted by resonances in the large, open mouth cavity ( Vossen et al. 2010 ). Auditory nerve recordings are sensitive to both interaural time differences (ITD) and interaural level differences (ILD), reflecting the acoustical interactions of direct and indirect sound components at the eardrum. Best ITD and click delays match interaural transmission delays, with a range of 200–500 μs. Inserting a mold in the mouth cavity blocks ITD and ILD sensitivity. Thus the neural response accurately reflects tympanic directionality, and most neurons in the auditory pathway should be directional.

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BOUCHERRAB, M., R. TIGRINE, B. BOURAHLA, and A. KHATER. "SCATTERING BY AN ADSORBED CHAIN ON METALLIC HEXAGONAL SURFACE." International Journal of Modern Physics B 28, no. 01 (December 11, 2013): 1350199. http://dx.doi.org/10.1142/s0217979213501993.

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We develop a theoretical approach to calculate the scattering and localization properties in the inhomogeneous hexagonal nanostructure system with adsorbed chain. Our numerical results are presented for three different positions of the defect, Top, Hollow and Bridge. The breakdown of translation symmetry induced by the inhomogeneity, gives rise to localized elastic wave modes at its neighborhood. The Landauer and Buttiker method is used to analyze the elastic wave scattering phenomena for atomic sites that constitute a minimum representation set in the neighborhood of the defect. The transmission and reflection probabilities as well as the phonons average transmittance across and the vibration density of states are determined for a large band of incident scattering energies. The coherent coupling between the localized elastic wave and the propagating modes of the perfect hexagonal structure leads to Fano resonances in the phononic conductance spectra of the studied structure. This is directly related to the measurable physical thermal conductivity of the perturbed domain.

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Ding, Xiu-Huan, Rui Wang, Qian Qiao, and Cun-Xi Zhang. "Linear and nonlinear Fano resonance in the main chain-structure of additional defects with an isolated ring composed of defects." Modern Physics Letters B 32, no. 07 (March 5, 2018): 1850089. http://dx.doi.org/10.1142/s0217984918500896.

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As is well known, Fano resonance originates from the interference between a continuum energy band and an embedded discrete energy level. We study transmission properties of the discrete chain-structure of additional defects with an isolated ring composed of N defect states, and obtain the analytical transmission coefficient of similar Fano formula. Using the formula, we reveal conditions for perfect reflections and transmissions due to either destructive or constructive interferences. It is found that a nonlinear Kerr-like response leads to bistable transmission, and for either linear cases or nonlinear ones, the defects in main arrays have a major impact on perfect reflections, but has no effect on perfect transmission.

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Stone, A. Douglas, William R. Sweeney, Chia Wei Hsu, Kabish Wisal, and Zeyu Wang. "Reflectionless excitation of arbitrary photonic structures: a general theory." Nanophotonics 10, no. 1 (October 1, 2020): 343–60. http://dx.doi.org/10.1515/nanoph-2020-0403.

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AbstractWe outline and interpret a recently developed theory of impedance matching or reflectionless excitation of arbitrary finite photonic structures in any dimension. The theory includes both the case of guided wave and free-space excitation. It describes the necessary and sufficient conditions for perfectly reflectionless excitation to be possible and specifies how many physical parameters must be tuned to achieve this. In the absence of geometric symmetries, such as parity and time-reversal, the product of parity and time-reversal, or rotational symmetry, the tuning of at least one structural parameter will be necessary to achieve reflectionless excitation. The theory employs a recently identified set of complex frequency solutions of the Maxwell equations as a starting point, which are defined by having zero reflection into a chosen set of input channels, and which are referred to as R-zeros. Tuning is generically necessary in order to move an R-zero to the real frequency axis, where it becomes a physical steady-state impedance-matched solution, which we refer to as a reflectionless scattering mode (RSM). In addition, except in single-channel systems, the RSM corresponds to a particular input wavefront, and any other wavefront will generally not be reflectionless. It is useful to consider the theory as representing a generalization of the concept of critical coupling of a resonator, but it holds in arbitrary dimension, for arbitrary number of channels, and even when resonances are not spectrally isolated. In a structure with parity and time-reversal symmetry (a real dielectric function) or with parity–time symmetry, generically a subset of the R-zeros has real frequencies, and reflectionless states exist at discrete frequencies without tuning. However, they do not exist within every spectral range, as they do in the special case of the Fabry–Pérot or two-mirror resonator, due to a spontaneous symmetry-breaking phenomenon when two RSMs meet. Such symmetry-breaking transitions correspond to a new kind of exceptional point, only recently identified, at which the shape of the reflection and transmission resonance lineshape is flattened. Numerical examples of RSMs are given for one-dimensional multimirror cavities, a two-dimensional multiwaveguide junction, and a multimode waveguide functioning as a perfect mode converter. Two solution methods to find R-zeros and RSMs are discussed. The first one is a straightforward generalization of the complex scaling or perfectly matched layer method and is applicable in a number of important cases; the second one involves a mode-specific boundary matching method that has only recently been demonstrated and can be applied to all geometries for which the theory is valid, including free space and multimode waveguide problems of the type solved here.

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Xu, Lingyi, Jianjun Lai, Qinghua Meng, Changhong Chen, and Yihua Gao. "Near-Perfect Infrared Transmission Based on Metallic Hole and Disk Coupling Array for Mid-Infrared Refractive Index Sensing." Chemosensors 12, no. 1 (December 26, 2023): 3. http://dx.doi.org/10.3390/chemosensors12010003.

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Nanostructured color filters, particularly those generated by the extraordinary optical transmission (EOT) resonance of metal–dielectric nanostructures, have been intensively studied over the past few decades. In this work, we propose a hybrid array composed of a hole array and a disk array with the same working period within the 3–14 μm mid-infrared band. Through numerical simulations, near-perfect transmission (more than 99%) and a narrower linewidth at some resonance wavelengths were achieved, which is vital for highly sensitive sensing applications. This superior performance is attributed to the surface plasmon coupling resonance between the hole and disk arrays. A high tunability of the near-perfect transmission peak with varying structural parameters, characteristics of sensitivity to the background refractive index, and angle independence were observed. We expect that this metallic hole and disk coupling array is promising for use in various applications, such as in plasmon biosensors for the high-sensitivity detection of biochemical substances.

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Xiong, Lei, Hongwei Ding, Yuanfu Lu, and Guangyuan Li. "Active tuning of resonant lattice Kerker effect." Journal of Physics D: Applied Physics 55, no. 18 (February 10, 2022): 185106. http://dx.doi.org/10.1088/1361-6463/ac4ec5.

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Abstract The Kerker effect has been generalized in nanophotonics and meta-optics, and has recently been of great interest by relating it to various fascinating functionalities such as scattering management and perfect transmission, reflection or absorption. One of the most interesting generalizations is the resonant lattice Kerker effect in periodic nanostructures. However, its active tuning has not been explored yet. Here, we report, for the first time, the active control of the resonant lattice Kerker effect in periodic Ge2Se2Te5 nanodisks. By changing the crystalline fraction, we show that the electric dipole surface lattice resonance (ED-SLR), the magnetic dipole resonance (MDR), and thus the resonant lattice Kerker effect are all red-shifted. We therefore realize the transition from the ED-SLR to the resonant lattice Kerker effect, which enables multilevel tuning of reflection, transmission and absorption with modulation depths above 86%. Taking advantage of the MDR redshifts, we also observe broadband and multilevel tuning of transmissions with modulation depth of 87% over a broadband range of 588 nm. Our work establishes a new path for designing high-performance active nanophotonic devices.

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Feng, S. "Dual-Band Coherent Perfect Absorption/Thermal." Advanced Electromagnetics 2, no. 3 (February 15, 2014): 22. http://dx.doi.org/10.7716/aem.v2i3.230.

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Dual-band perfect absorption/thermal emission is shown to be a general property of an ultrathin bilayer consisting of a dielectric and a totally reflective layer if the permittivity of the dielectric can be described by Drude-Lorentz (DL) model. The two bands coexist and reside on opposite sides of the Lorentzian resonant frequency where the material loss is small. However, the perfect absorption mechanism for the two bands is distinguishably different. One band is related to Fabry-Perot phenomenon and the surge of refractive index near the Lorentzian resonance. This band is polarization insensitive. The other band is associated with excitation of Brewster-type mode at the ϵ-near-zero (ENZ) wavelength and occurs only for p-polarized wave at oblique incidences. This mode has a fast-wave non-radiative character and propagates along the ultrathin ENZ layer superimposed on the highly reflective surface. Both bands exhibit wide-angle high emission with a small shift in their center frequencies which can be tuned by tuning the Lorentzian resonance. The resonance-enhanced dual band absorption occurs in the ultrathin DL layer at the weakly absorbing wavelengths as a consequence of an interaction between the total transmission and the total reflection. We demonstrate this phenomenon in a silicon carbide/copper bilayer. The suggested structure may have applications in biological and chemical sensors, IR sensors, thermal emission controls, thermophotovoltaics, and photodetectors.

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Li, Su Ping, and Xiao Fei Chen. "Solar Wireless Charging Circuit System Designing." Applied Mechanics and Materials 229-231 (November 2012): 1017–20. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.1017.

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The solar wireless charging circuit system based on resonance coupling power wireless transmission is aimed at addressing long wire, complex manual operation of wire charging type and short-distance, low efficiency of general electromagnetic induction-type power wireless transmission. Solar is conversed to electricity by photoelectric conversion then the electricity passes the following processing circuit: solar power supply circuit, power wireless transmission circuit and lithium battery charging circuit to complete lithium battery charging finally. The proposed circuit system owns perfect long-distance transmission, safe-operation, automotive rechargeable, flexible and efficient etc basic features and preventing over charge and over discharge double protection performance.

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Fang, Yun-Tuan, Han-Qing He, and Zhi-Li Lin. "Nonreciprocal perfect absorber based on an ultra-compact nonsymmetry cavity structure." International Journal of Modern Physics B 29, no. 03 (January 26, 2015): 1550001. http://dx.doi.org/10.1142/s0217979215500010.

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In this paper, the transmission and absorption properties of nonsymmetrical cavity structure with metal material have been studied through transfer matrix method and electromagnetic (EM) field simulations. The absorption is found to be dependent on the cavity resonance effect. For a nonsymmetrical structure, the EM wave can be totally absorbed from one incidence direction, at the same time the EM wave is totally reflected from the opposite incidence direction. The reasons of the nonreciprocal absorption are analyzed in detail.

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Chen, Shi Bin, Yun Shi Yao, and Rui Long Wang. "Fabrication of Diamond-Structure Alumina Photonic Crystal with Rectangle Cavity Defect and its Microwave Properties." Applied Mechanics and Materials 423-426 (September 2013): 34–37. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.34.

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A diamond-structure alumina photonic crystal with a rectangle cavity defect has been fabricated combining stereolithography (SL) and gel-casting. In transmission spectra a resonance peak of transmission of 70% is observed in the band gap of 10.48Ghz-12.21Ghz, by comparing with the measured result of the perfect structure and theoretical calculations. Experimental results showed that the peak of photonic band gap was caused by the rectangle cavity defect of the diamond structural photonic crystal. The method provides us with a novel approach to fabricate ceramic microwave photonic crystals with point defect.

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Mahato, Hari Shankar. "Upscaling of Helmholtz Equation Originating in Transmission through Metallic Gratings in Metamaterials." Scientific World Journal 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/7436136.

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We investigate the transmission properties of a metallic layer with narrow slits. We consider (time-harmonic) Maxwell’s equations in theH-parallel case with a fixed incident wavelength. We denoteη>0as the typical size of the complex structure and obtain the effective equations by lettingη→0. For metallic permittivities with negative real part, plasmonic waves can be excited on the surfaces of the slits. For the waves to be in resonance with the height of the metallic layer, the corresponding results can be perfect transmission through the layer.

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Dash, Sasmita, Christos Liaskos, Ian F. Akyildiz, and Andreas Pitsillides. "Graphene Hypersurface for Manipulation of THz Waves." Materials Science Forum 1009 (August 2020): 63–68. http://dx.doi.org/10.4028/www.scientific.net/msf.1009.63.

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In this work, we investigated graphene hypersurface (HSF) for the manipulation of THz waves. The graphene HSF structure is consists of a periodic array of graphene unit cells deposited on silicon substrate and terminated by a metallic ground plane. The performance of the proposed HSF is numerically analyzed. Electromagnetic parameters of HSF such as permeability, permittivity, and impedance are studied. The proposed graphene HSF has active control over absorption, reflection, and transmission of THz waves. The graphene HSF provides perfect absorption, zero reflection and zero transmission at resonance. Moreover, the graphene HSF structure has the advantage of anomalous reflection and frequency reconfiguration. Incident waves can be reflected in the desired direction, depending on the phase gradient of the HSF and the perfect absorption is maintained at all reconfigurable frequencies upon reconfiguration. The results reveal the effectiveness of the graphene HSF for the manipulation of THz waves.

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Zheng, H. Y., X. R. Jin, J. W. Park, Y. H. Lu, Joo Yull Rhee, W. H. Jang, H. Cheong, and Y. P. Lee. "Tunable dual-band perfect absorbers based on extraordinary optical transmission and Fabry-Perot cavity resonance." Optics Express 20, no. 21 (October 4, 2012): 24002. http://dx.doi.org/10.1364/oe.20.024002.

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Ge, Hongyi, Li Li, Yuying Jiang, Guangming Li, Fei Wang, Ming Lv, and Yuan Zhang. "Design of High-performance Terahertz Sensor Based on Metamaterials." Journal of Physics: Conference Series 2174, no. 1 (January 1, 2022): 012001. http://dx.doi.org/10.1088/1742-6596/2174/1/012001.

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Abstract In this paper, a high-performance terahertz sensor is proposed. The sensor obtains a perfect narrow-band transmission spectrum at 3.842 THz with a Q value of 137 at the resonance frequency. The sensitivity reaches 160 GHz/RIU at the thickness of the substance to be measured of 10 μm, with good sensing performance. The results show that it has a promising application in terahertz high-sensitivity biosensing detection.

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YAO, JIAN-MING, SHI-LAI WANG, JIAN-MING WANG, and CHENG-ZHI YE. "A NECESSARY CONDITION OF FANO SWITCHING AND WAVE TRANSMISSION THROUGH THE CHAIN-STRUCTURE WITH TWO DEFECTS." Modern Physics Letters B 26, no. 04 (February 10, 2012): 1150024. http://dx.doi.org/10.1142/s0217984911500242.

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We consider a discrete model that describes a linear chain of particles coupled to two defects. This model can be regarded as a linear generalization of the familiar Fano–Anderson model. The analytical result for the plane wave transmission coefficient is obtained. Comparing the transmission coefficient of Gaussian wave with that of plane wave, we can draw a conclusion that arising perfect reflection due to destructive interference depends on the input waveform of incident particle and a necessary switching condition of Fano resonance is the input plane wave. This interesting feature may play a guiding role in devising various particle switches in theory and experiment.

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Wu, Pinghui, Zeqiang Chen, Danyang Xu, Congfen Zhang, and Ronghua Jian. "A Narrow Dual-Band Monolayer Unpatterned Graphene-Based Perfect Absorber with Critical Coupling in the Near Infrared." Micromachines 11, no. 1 (January 1, 2020): 58. http://dx.doi.org/10.3390/mi11010058.

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The combination of critical coupling and coupled mode theory in this study elevated the absorption performance of a graphene-based absorber in the near-infrared band, achieving perfect absorption in the double bands (98.96% and 98.22%), owing to the guided mode resonance (the coupling of the leak mode and guided mode under the condition of phase matching, which revealed 100% transmission or reflection efficiency in the wavelet band), and a third high-efficiency absorption (91.34%) emerged. During the evaluation of the single-structure, cross-circle-shaped absorber via simulation and theoretical analysis, the cross-circle shaped absorber assumed a conspicuous preponderance through exploring the correlation between absorption and tunable parameters (period, geometric measure, and incident angle of the cross-circle absorber), and by briefly analyzing the quality factors and universal applicability. Hence, the cross-circle resonance structure provides novel potential for the design of a dual-band unpatterned graphene perfect absorber in the near-infrared band, and possesses practical application significance in photoelectric detectors, modulators, optical switching, and numerous other photoelectric devices.

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Dang, Phuc Toan, Khai Q. Le, Quang Minh Ngo, Hieu Pham Trung Nguyen, and Truong Khang Nguyen. "Guided-mode Resonance Filter with Ultra-narrow Bandwidth over the Visible Frequencies for Label-free Optical Biosensor." Journal of Advanced Engineering and Computation 3, no. 2 (June 30, 2019): 406. http://dx.doi.org/10.25073/jaec.201932.233.

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A practical guided-mode resonance filter operating in the visible band of the electromagnetic spectrum is numerically designed in this paper. The filter provides high background transmission (>90%) with almost perfect reflection at resonance wavelengths of 623 nm and 641 nm for TE and TM modes, respectively. Our filter is also characterized by its sensitivity to incident angles, polarizations, and a refractive index of the surrounding environment which are utilized in practical applications such as tunable optical filters, imaging or detection. We show that the resonant transmission spectral response can be used for highly sensitive, a potential label-free refractive index biosensor having sensitivities of 90 nm/RIU and 103 nm/RIU, and figure of merits of 1.93 and 2.13 for TM and TE polarizations, respectively.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.

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Lee, Taejun, Joohoon Kim, Ishwor Koirala, Younghwan Yang, Trevon Badloe, Jaehyuck Jang, and Junsuk Rho. "Nearly Perfect Transmissive Subtractive Coloration through the Spectral Amplification of Mie Scattering and Lattice Resonance." ACS Applied Materials & Interfaces 13, no. 22 (May 28, 2021): 26299–307. http://dx.doi.org/10.1021/acsami.1c03427.

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Do, M. A., H. J. Lee, J. H. Yeum, Y. M. Chang, H. D. Ghim, and Jin Hyun Choi. "Ultra-Small Superparamagnetic Iron Oxide Nanoparticles as MRI Contrast Enhancing Agents." Advanced Materials Research 47-50 (June 2008): 1076–79. http://dx.doi.org/10.4028/www.scientific.net/amr.47-50.1076.

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Ultrasmall superparamagnetic iron oxide nanoparticles (USPION) as magnetic resonance imaging were synthesized through a sonochemical co-precipitation method with poly (ethyleneimine) (PEI). The size of the USPION was controlled by poly (ethyleneimine) (PEI) contents, ultrasonic exposure time, and Na4OH concentration. The characteristics of PEI-USPION were studied by X-ray diffractometry, magnetic property measurement system, scanning electron microscopy, transmission electron microscopy, and particle size analysis. The PEI-USPION had an average size of 5~10nm with a narrow size distribution, a perfect magnetite crystal structure, and high saturation magnetization.

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Wang, Jincheng, Hengli Feng, Jingyu Zhang, Zuoxin Zhang, Chang Liu, Dongchao Fang, Lingling Ran, and Yang Gao. "Polarization-insensitive metamaterial perfect absorber in near-infrared band based on trapezoidal silver array." Laser Physics 33, no. 9 (July 24, 2023): 095802. http://dx.doi.org/10.1088/1555-6611/ace70f.

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Abstract In this article, we presented our proposal for a metamaterial perfect absorber (MPA) operating in the near-infrared band. Our MPA comprised a trapezoidal silver layer, a substrate layer, and an intermediate alumina layer. The transmission characteristics of MPA were analyzed by the three-dimensional (3D) finite difference time domain method. The simulation results were analyzed by equivalent circuit theory. The results show that the MPA achieved 100% absorption of transverse magnetic (TM) polarization and transverse electric (TE) polarization with resonance wavelength λ = 1492.5 nm. By varying the length of the bottom side of the trapezoid, the MPA’s resonance wavelength could be effectively tuned, and the absorption was maintained at above 99%. With the incidence angle of 0°–55°, the absorption remains above 90% at TE polarization and above 80% at 55°–70°. The absorption at the TM polarization remains above 99% when the incident angle is 0°–70°. A wide angle of incidence and good absorption were achieved. The sensitivity (S) and figure of merit were 228 nm/refractive index unit and 1378 RIU−1, respectively. The proposed absorber with excellent absorption in the range of infrared spectra has a promising application potential in fields such as energy harvesting and infrared sensors.

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Lu, Taiguo, Dawei Zhang, Peizhen Qiu, Jiqing Lian, Ming Jing, Binbin Yu, Jing Wen, and Songlin Zhuang. "Dual-Band Perfect Metamaterial Absorber Based on an Asymmetric H-Shaped Structure for Terahertz Waves." Materials 11, no. 11 (November 6, 2018): 2193. http://dx.doi.org/10.3390/ma11112193.

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We designed an ultra-thin dual-band metamaterial absorber by adjusting the side strips’ length of an H-shaped unit cell in the opposite direction to break the structural symmetry. The dual absorption peaks approximately 99.95% and 99.91% near the central resonance frequency of 4.72 THz and 5.0 THz were obtained, respectively. Meanwhile, a plasmon-induced transmission (PIT) like reflection window appears between the two absorption frequencies. In addition to theoretical explanations qualitatively, a multi-reflection interference theory is also investigated to prove the simulation results quantitatively. This work provides a way to obtain perfect dual-band absorption through an asymmetric metamaterial structure, and it may achieve potential applications in a variety of fields including filters, sensors, and some other functional metamaterial devices.

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Oubeniz, Hammou, Abdelhaq Belkacem, Hicham Mangach, Muamer Kadic, Abdenbi Bouzid, and Younes Achaoui. "Controlled Dispersion and Transmission-Absorption of Optical Energy through Scaled Metallic Plate Structures." Materials 16, no. 18 (September 10, 2023): 6146. http://dx.doi.org/10.3390/ma16186146.

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The dispersive feature of metals at higher frequencies has opened up a plethora of applications in plasmonics. Besides, Extraordinary Optical Transmission (EOT) reported by Ebbesen et al. in the late 90’s has sparked particular interest among the scientific community through the unprecedented and singular way to steer and enhance optical energies. The purpose of the present paper is to shed light on the effect of the scaling parameter over the whole structure, to cover the range from the near-infrared to the visible, on the transmission and the absorption properties. We further bring specific attention to the dispersive properties, easily extractable from the resonance frequency of the drilled tiny slits within the structure. A perfect matching between the analytical Rigorous Coupled Wave Analysis (RCWA), and the numerical Finite Elements Method (FEM) to describe the underlying mechanisms is obtained.

30

Kullig, Julius, and Jan Wiersig. "Ray–Wave Correspondence in Microstar Cavities." Entropy 24, no. 11 (November 5, 2022): 1614. http://dx.doi.org/10.3390/e24111614.

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In a previous work by the authors (Phys. Rev. Research 2, 012072(R) (2020)) a novel concept of light confinement in a microcavity was introduced which is based on successive perfect transmissions at Brewster’s angle. Hence, a new class of open billiards was designed with star-shaped microcavities where rays propagate on orbits that leave and re-enter the cavity. In this article, we investigate the ray–wave correspondence in microstar cavities. An unintuitive difference between clockwise and counterclockwise propagation is revealed which is traced back to nonlinear resonance chains in phase space.

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Entezar, S. Roshan, and R. Vatannejad. "1D graded thickness nonlinear structure as an optical diode." Journal of Nonlinear Optical Physics & Materials 25, no. 03 (September 2016): 1650030. http://dx.doi.org/10.1142/s0218863516500302.

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The linear and nonlinear optical properties of a defective one-dimensional (1D) graded thickness nonlinear structure are investigated using the well-known transfer matrix method. It is shown that the structure can support a perfect transmission resonance (defect mode) in its forbidden band gap. The frequency of such a defect mode is independent from the value of the thickness modulation parameter. However, its Q-factor decreases and the spatial asymmetry of the structure increases by increasing the thickness modulation parameter. Due to the large spatial asymmetry of the structure, the nonlinear properties of the structure are sensitive to the direction of the impinging light and the structure acts as an optical.

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FIORINA, JOCELYN, DAVID ROUSSEAU, and FRANÇOIS CHAPEAU-BLONDEAU. "INTERFERER REJECTION IMPROVED BY NOISE IN ULTRA-WIDEBAND TELECOMMUNICATIONS." Fluctuation and Noise Letters 06, no. 03 (September 2006): L317—L328. http://dx.doi.org/10.1142/s021947750600346x.

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Ultra-wideband technology uses baseband transmission of low-power ultra-short information-bearing impulses, and represents a promising approach for very-high speed wireless communications with multiple access, as well as for low-rate high-accuracy positioning systems. The first demonstrations of the huge potential of ultra-wideband were based on hypotheses of perfect power control and multiuser interferences modeled as white Gaussian noise. Here, by explicitly modeling the interference with an external impulse signal, we demonstrate the possibility of improving the rejection of the interferer thanks to a constructive action of the noise. This is interpreted as a novel instance of the phenomenon of stochastic resonance or improvement by noise in signal processing.

33

Liberal, Iñigo, Yue Li, and Nader Engheta. "Reconfigurable epsilon-near-zero metasurfaces via photonic doping." Nanophotonics 7, no. 6 (June 27, 2018): 1117–27. http://dx.doi.org/10.1515/nanoph-2018-0012.

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AbstractThe next generation of flat optic devices aspires to a dynamic control of the wavefront characteristics. Here, we theoretically investigated the reconfigurable capabilities of an epsilon-near-zero (ENZ) metasurface augmented with resonant dielectric rods. We showed that the transmission spectrum of the metasurface is characterized by a Fano-like resonance, where the metasurface behavior changed from perfect magnetic conductor to epsilon-and-mu-near-zero material responses. The abrupt variation between these two extreme material responses suggests potential applications in dynamic metasurfaces. We highlighted the causality aspects of ENZ metasurfaces with a transient analysis and numerically investigated different reconfigurable mechanisms. Thus, this work introduces a new strategy for dynamic wavefront engineering.

34

Abov, Yu G., N. O. Elyutin, D. V. Lvov, and A. N. Tyulyusov. "On the Possibility of Observing the Effect of Anomalous Neutron Transmission in Predominantly Resonance Absorption by Perfect Crystals of InSb." Physics of Atomic Nuclei 82, no. 4 (July 2019): 309–16. http://dx.doi.org/10.1134/s1063778819040033.

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Rubín-Osanz, M., M. C. de Ory, I. Gimeno, D. Granados, D. Zueco, A. Gomez, and F. Luis. "Coupling organic free-radical molecules to lumped-element superconducting resonators." Low Temperature Physics 50, no. 6 (June 1, 2024): 472–80. http://dx.doi.org/10.1063/10.0026086.

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A promising route toward the realization of a molecular spin quantum processor relies on coupling magnetic molecules to individual photons confined within superconducting resonators. As a simple approximation to such a hybrid scheme, here we explore the conditions that determine the collective coupling of DPPH organic free radicals to lumped-element LC superconducting resonators. In these chips, multiple resonators are coupled to a single readout line. This enables designing the relevant resonator properties, such as resonance frequency, cavity volume, and impedance while keeping a perfect transmission for the device. Here, we exploit these design possibilities to achieve a coherent spin-photon coupling regime. Besides, we study how this coupling depends on the relative orientation of the external dc magnetic field concerning the photon magnetic field and the spins locations concerning the chip surface.

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Kumari, G. Vimala, G. Sasibhushana Rao, and B. Prabhakara Rao. "NEW BACTERIA FORAGING AND PARTICLE SWARM HYBRID ALGORITHM FOR MEDICAL IMAGE COMPRESSION." Image Analysis & Stereology 37, no. 3 (December 6, 2018): 249. http://dx.doi.org/10.5566/ias.1865.

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For perfect diagnosis of brain tumour, it is necessary to identify tumour affected regions in the brain in MRI (Magnetic Resonance Imaging) images effectively and compression of these images for transmission over a communication channel at high speed with better visual quality to the experts. An attempt has been made in this paper for identifying tumour regions with optimal thresholds which are optimized with the proposed Hybrid Bacteria Foraging Optimization Algorithm (BFOA) and Particle Swarm Optimization (PSO) named (HBFOA-PSO) by maximizing the Renyi’s entropy and Kapur’s entropy. BFOA may be trapped into local optimal problem and delay in execution time (convergence time) because of random chemo taxis steps in the procedure of algorithm and to get global solution, a theory of swarming is commenced in the structure of HBFOA-PSO. Effectiveness of this HBFOA-PSO is evaluated on six different MRI images of brain with tumours and proved to be better in Peak Signal to Noise Ratio (PSNR), Mean Square Error (MSE) and Fitness Function.

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Simone, Giuseppina. "Demonstrating more than 2π phase modulation in non-Hermitian asymmetric multilayers". New Journal of Physics 25, № 12 (1 грудня 2023): 123027. http://dx.doi.org/10.1088/1367-2630/ad0f3c.

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Abstract Phase modulation has come to be recognized as a fundamental paradigm for optical device design in applications involving the spatiotemporal control of optical wavefronts. Here, the cavities use a combination of absorptive and lossless layers with ideal conductive metal to control reflection and phase shift, similar to the Fabry–Pérot system, which has zero reflection and perfect transmission. Multilayers with different sequences and composed of several stack layers were examined for reflectivity when activated in a prism-coupled layout. The layer’s different arrangements, resulting in open and closed asymmetric multilayers, display reflectance spectra with distinct features as well as phase and shifts. In the open configuration, there is a strong coupling between the hybridized resonance mode and the exciton from the red dye. As a result, energy-based topological considerations identify a correlation between exciton/polariton strong coupling, topological darkness, and phase tuning, and they motivate the 3 π phase shift range.

38

Li, Xingyu, Dingquan Liu, Junli Su, Leihao Sun, Haihan Luo, Gang Chen, Chong Ma, and Qiuyu Zhang. "Enhanced Near-Infrared Ultra-Narrow Absorber Based on a Dielectric Nano-Resonant Ring for Refractive Index Sensing." Sensors 23, no. 20 (October 12, 2023): 8402. http://dx.doi.org/10.3390/s23208402.

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In this paper, a plasmon resonance-enhanced narrow-band absorber based on the nano-resonant ring array of transparent conductive oxides (TCOs) is proposed and verified numerically. Due to the unique properties of TCOs, the structure achieves an ultra-narrowband perfect absorption by exhibiting a near-field enhancement effect. Consequently, we achieve a peak absorption rate of 99.94% at 792.2 nm. The simulation results indicate that the Full Width Half Maximum (FWHM) can be limited to within 8.8 nm. As a refractive index sensor, the device reaches a sensitivity S of 300 nm/RIU and a Figure of Merit (FOM) value of 34.1 1/RIU. By analyzing the distribution characteristics of the electromagnetic field at the 792.2 nm, we find high absorption with a narrow FWHM of the ITO nano-resonant ring (INRR) owing to plasmon resonance excited by the free carriers at the interface between the metal and the interior of the ITO. Additionally, the device exhibits polarization independence and maintains absorption rates above 90% even when the incident formed by the axis perpendicular to the film is greater than 13°. This study opens a new prospective channel for research into TCOs, which will increase the potential of compact photoelectric devices, such as optical sensing, narrowband filtering, non-radiative data transmission and biomolecular manipulation.

39

Lamb, Kevin G., and Raymond T. Pierrehumbert. "Steady-state nonlinear internal gravity-wave critical layers satisfying an upper radiation condition." Journal of Fluid Mechanics 238 (May 1992): 371–404. http://dx.doi.org/10.1017/s0022112092001757.

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We consider the behaviour of an internal gravity wave encountering a critical level in a stratified fluid, assuming the critical-level flow to be dominated by nonlinear effects. The background flow is a shear layer, and the stratification is sufficiently strong to support wave propagation everywhere. Incident and reflected waves are permitted below the critical level, and a radiation condition is imposed far above it. For this geometry we construct, by a combination of asymptotic and numerical means, steady, nonlinear solutions, and discuss the associated transmission coefficients, reflection coefficients, phase shifts, and resonance positions when the system is forced from below.The inviscid solutions we exhibit have continuous density and velocity everywhere, and so do not require the introduction of internal viscous boundary layers. Further, the streamlines bounding the recirculating cat's-eye regions have corners, just as in the unstratified case. For weak stratification, the transmitted wave is nearly as strong as the incident wave, and there is accompanying strong over-reflection. As the stratification increases, the critical level becomes a nearly perfect reflector. The amount of transmission depends on wave amplitude, and the sensitivity increases with increasing stratification.There are regions of parameter space for which steady solutions could not be found. The critical-layer structure appears to break down by unbounded thickening when the stratification becomes too strong, suggesting that in these cases some neglected physical process must intervene to limit growth of the recirculating region.

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Szczepańska, Elżbieta, Anna Synak, Piotr Bojarski, Paweł Niedziałkowski, Anna Wcisło, Tadeusz Ossowski, and Beata Grobelna. "Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence." Materials 13, no. 22 (November 16, 2020): 5168. http://dx.doi.org/10.3390/ma13225168.

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The present work describes synthesis, characterization, and use of a new dansyl-labelled Ag@SiO2 nanocomposite as an element of a new plasmonic platform to enhance the fluorescence intensity. Keeping in mind that typical surface plasmon resonance (SPR) characteristics of silver nanoparticles coincide well enough with the absorption of dansyl molecules, we used them to build the core of the nanocomposite. Moreover, we utilized 10 nm amino-functionalized silica shell as a separator between silver nanoparticles and the dansyl dye to prevent the dye-to-metal energy transfer. The dansyl group was incorporated into Ag@SiO2 core-shell nanostructures by the reaction of aminopropyltrimethoxysilane with dansyl chloride and we characterized the new dansyl-labelled Ag@SiO2 nanocomposite using transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR). Additionally, water wettability measurements (WWM) were carried out to assess the hydrophobicity and hydrophilicity of the studied surface. We found that the nanocomposite deposited on a semitransparent silver mirror strongly increased the fluorescence intensity of dansyl dye (about 87-fold) compared with the control sample on the glass, proving that the system is a perfect candidate for a sensitive plasmonic platform.

41

Hainey, Mel F., Takaaki Mano, Takeshi Kasaya, Tetsuyuki Ochiai, Hirotaka Osato, Kazuhiro Watanabe, Yoshimasa Sugimoto, et al. "Near-field resonant photon sorting applied: dual-band metasurface quantum well infrared photodetectors for gas sensing." Nanophotonics 9, no. 16 (October 8, 2020): 4775–84. http://dx.doi.org/10.1515/nanoph-2020-0456.

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AbstractTwo photodetectors for measuring transmission and two bulky, separated narrowband filters for picking a target gas absorption line and a non-absorbing reference from broadband emission are typically required for dual-band non-dispersive infrared (NDIR) gas sensing. Metal-dielectric-metal (MDM) metasurface plasmon cavities, precisely controllable narrowband absorbers, suggest a next-generation, nanophotonic approach. Here, we demonstrate a dual-band MDM cavity detector that consolidates the function of two detectors and two filters into a single device by employing resonant photon sorting-a function unique to metasurfaces. Two MDM cavities sandwiching a quantum well infrared photodetector (QWIP) with distinct resonance wavelengths are alternately arranged in a subwavelength period. The large absorption cross section of the cavities ensures ~95% efficient lateral sorting of photons by wavelength into the corresponding detector within a near-field region. The flow of incident photons is thus converted into two independent photocurrents for dual-band detection. Our dual-band photodetectors show competitive external quantum efficiencies up to 38% (responsivity 2.1 A/W, peak wavelength 6.9 5m) at 78 K. By tailoring one resonance to an absorption peak of NO2 (6.25 5m) and the other to a non-absorbing reference wavelength (7.15 5m), NDIR NO2 gas sensing with 10 ppm accuracy and 1 ms response times is demonstrated. Through experiment and numerical simulation, we confirm near-perfect absorption at the resonant cavity and suppressed absorption at its non-resonant counterpart, characteristic of resonant photon sorting. Dual-band sensing across the mid-infrared should be possible by tailoring the cavities and quantum well to desired wavelengths.

42

Vanhecke, Dimitri, Federica Crippa, Marco Lattuada, Sandor Balog, Barbara Rothen-Rutishauser, and Alke Petri-Fink. "Characterization of the Shape Anisotropy of Superparamagnetic Iron Oxide Nanoparticles during Thermal Decomposition." Materials 13, no. 9 (April 25, 2020): 2018. http://dx.doi.org/10.3390/ma13092018.

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Magnetosomes are near-perfect intracellular magnetite nanocrystals found in magnetotactic bacteria. Their synthetic imitation, known as superparamagnetic iron oxide nanoparticles (SPIONs), have found applications in a variety of (nano)medicinal fields such as magnetic resonance imaging contrast agents, multimodal imaging and drug carriers. In order to perform these functions in medicine, shape and size control of the SPIONs is vital. We sampled SPIONs at ten-minutes intervals during the high-temperature thermal decomposition reaction. Their shape (sphericity and anisotropy) and geometric description (volume and surface area) were retrieved using three-dimensional imaging techniques, which allowed to reconstruct each particle in three dimensions, followed by stereological quantification methods. The results, supported by small angle X-ray scattering characterization, reveal that SPIONs initially have a spherical shape, then grow increasingly asymmetric and irregular. A high heterogeneity in volume at the initial stages makes place for lower particle volume dispersity at later stages. The SPIONs settled into a preferred orientation on the support used for transmission electron microscopy imaging, which hides the extent of their anisotropic nature in the axial dimension, there by biasing the interpretation of standard 2D micrographs. This information could be feedback into the design of the chemical processes and the characterization strategies to improve the current applications of SPIONs in nanomedicine.

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Abdussalam-Mohammed, Wanisa, Mohamed Y. Najem, Asma Omar Errayes, Shamsi Saad Shamsi, Moftah Omar Darwish, and Aysha B. Mezoughi. "Synthesis of Highly Stabilized AuNPs Using 3,5-Dinitrobenzoic Acid and Sodium Acetate as Capping Agents in an Aqueous Solution and their Bioactivity." Journal of Nano Research 70 (October 25, 2021): 67–79. http://dx.doi.org/10.4028/www.scientific.net/jnanor.70.67.

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Gold nanoparticles (AuNPs) have received considerable attention recently because of their chemical properties and potential applications in the medical field.Monodispersed AuNPs in this paper are successfully synthesized by using some stabilized ligands including 3,5-dinitrobenzoic acid (DNBA) and sodium acetate (SA) dispersible in aqueous media, where NaBH4 was used as a reducing agent to reduce KAuCl4 from Au (III) to Au (0).The synthesized AuNPs are characterized by using UV–Vis spectroscopy to evaluate their surface plasmon resonance (SPR) absorption in a wavelength range of 500–650 nm. The size and morphology of AuNPs were determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS), where the results displayed that AuNPs with a strong SPR peak around 530 nm and 536 nm with an average size of 10 ± 1.2 nm and 14.0 ± 0.9 nm at the initial time for both DNBA-AuNP and SA-AuNP respectively. The synthesized AuNPs illustrate perfect chemical stability for more than 24 weeks in an aqueous solution. Therefore, the size of DNBA-AuNP was smaller and most stable than SA-AuNP, which may be due to 2 nitro groups that have resonance with the benzene ring leading to an increase in the stability of AuNPs.The stability of AuNPs in this work was monitored at a range of pH 2-12. Where high stability was showed at pH 6.6 ± 0.5, while the aggregation appears at more than pH 10 and less than pH.3.5.Herein, in this paper AuNPs have shown remarkable results against multi-drug resistance Pseudomonas aeruginosa. AuNP functionalized by SA ligand is shown to have a greater biological effect and be more effective than DNBA-AuNP. Due to the high stability of AuNP prepared in this work, it can be further tested to be an improved choice for more biomedical applications in the future.

44

Nigmatullin, Raoul R., Paolo Lino, and Guido Maione. "“Fuzzy” calculus: The link between quantum mechanics and discrete fractional operators." Fractional Calculus and Applied Analysis 23, no. 3 (June 25, 2020): 764–86. http://dx.doi.org/10.1515/fca-2020-0038.

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AbstractIn this paper, based on the “fuzzy” calculus covering the continuous range of operations between two couples of arithmetic operations (+, –) and (×, :), a new form of the fractional integral is proposed occupying an intermediate position between the integral and derivative of the first order. This new form of the fractional integral satisfies the C1 criterion according to the Ross classification. The new calculus is tightly related to the continuous values of the continuous spin S = 1 and can generalize the expression for the fractional values of the shifting discrete index. This calculus can be interpreted as the appearance of the hidden states corresponding to unobservable values of S = 1. Many well-known formulas can be generalized and receive a new extended interpretation. In particular, one can factorize any rectangle matrix and receive the “perfect” filtering formula that allows transforming any (deterministic or random) function to another arbitrary function and vice versa. This transformation can find unexpected applications in data transmission, cryptography and calibration of different gadgets and devices. One can also receive the hybrid (”centaur”) formula for the Fourier (F-) transformation unifying both expressions for the direct and inverse F-transformations in one mathematical unit. The generalized Dirichlet formula, which is obtained in the frame of the new calculus to allow selecting the desired resonance frequencies, will be useful in discrete signals processing, too. The basic formulas are tested numerically on mimic data.

45

POTEMSKI, M. "LANDAU LEVEL SPECTROSCOPY OF DIRAC-LIKE FERMIONS IN MULTILAYER GRAPHENE." International Journal of Modern Physics B 23, no. 12n13 (May 20, 2009): 2665–66. http://dx.doi.org/10.1142/s0217979209062141.

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The results of spectroscopic (magneto-transmission and Raman scattering) studies1–8 of multilayers of carbon which are thermally decomposed from carbon-terminated surface of silicon carbide, and of thin layers of highly oriented pyrolytic and natural graphite were presented. Those carbon multilayers on silicon carbide which are not directly affected by the SiC / C interface and which in consequence are nearly charge neutral show the magneto-optical properties identical with the properties characteristic of a single graphite sheet, graphene. Inter Landau level transitions in this multilayer graphene have been studied in a wide spectral range from far-infrared to almost visible region. The dispersion relations of electronic states are found to reflect the form of the Dirac cone with almost perfect electron-hole symmetry and only weak deviations from linearity at high energies. Cyclotron resonance transition in multilayer graphene can be observed in magnetic fields down to 40 mT, and its width is practically independent on temperature up to 300 K. Such parameters as carrier mobility and minimal conductivity as well as the possibility to probe the immediate vicinity of the Dirac point were evaluated and discussed in detail. For comparison, the magneto-optical properties of thin layers of bulk graphite were also reported. The Dirac like electronic dispersion relations are also found in these systems, but only in the vicinity of the particular (H) point of the Brillouin zone. In general, the measured spectra are, however, more complex and reflect the three-dimensional character of graphene layers with Bernal stacking. Note from Publisher: This article contains the abstract only.

46

Chen, Lin, YuMing Wei, XiaoFei Zang, YiMing Zhu, and SongLin Zhuang. "Excitation of dark multipolar plasmonic resonances at terahertz frequencies." Scientific Reports 6, no. 1 (February 23, 2016). http://dx.doi.org/10.1038/srep22027.

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Abstract We experimentally observe the excitation of dark multipolar spoof localized surface plasmon resonances in a hybrid structure consisting of a corrugated metallic disk coupled with a C-shaped dipole resonator. The uncoupled corrugated metallic disk only supports a dipolar resonance in the transmission spectrum due to perfect symmetry of the structure. However, the dark multipolar spoof localized surface plasmon resonances emerge when coupled with a bright C-shaped resonator which is placed in the vicinity of the corrugated metallic disk. These excited multipolar resonances show minimum influence on the coupling distance between the C-shaped resonator and corrugated metallic disk. The resonance frequencies of the radiative modes are controlled by varying the angle of the C-shaped resonator and the inner disk radius, both of which play dominant roles in the excitation of the spoof localized surface plasmons. Observation of such a transition from the dark to radiative nature of multipolar spoof localized plasmon resonances would find potential applications in terahertz based resonant plasmonic and metamaterial devices.

47

Luo, Xiaoguang, Jian Shi, Yaoming Zhang, Ziang Niu, Dongpeng Miao, Huiru Mi, and Wei Huang. "Filtering electrons by mode coupling in finite semiconductor superlattices." Scientific Reports 12, no. 1 (May 7, 2022). http://dx.doi.org/10.1038/s41598-022-11449-5.

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AbstractElectron transmission through semiconductor superlattices is studied with transfer matrix method and resonance theory. The formation of electron band-pass transmission is ascribed to the coupling of different modes in those semiconductor superlattices with the symmetric unit cell. Upon Fabry-Pérot resonance condition, Bloch modes and two other resonant modes are identified to be related to the nature of the superlattice and its unit cell, respectively. The bands related to the unit cell and the superlattice overlap spontaneously in the tunneling region due to the shared wells, and the coupling of perfect resonances results in the band-pass tunneling. Our findings provide a promising way to study electronic systems with more complicated superlattices or even optical systems with photonic crystals.

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Collin, Stéphane, Grégory Vincent, Riad Haïdar, Nathalie Bardou, Sylvain Rommeluère, and Jean-Luc Pelouard. "Nearly Perfect Fano Transmission Resonances through Nanoslits Drilled in a Metallic Membrane." Physical Review Letters 104, no. 2 (January 15, 2010). http://dx.doi.org/10.1103/physrevlett.104.027401.

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49

Zhukovsky, Sergei V., and Andrey G. Smirnov. "All-optical diode action in asymmetric nonlinear photonic multilayers with perfect transmission resonances." Physical Review A 83, no. 2 (February 23, 2011). http://dx.doi.org/10.1103/physreva.83.023818.

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50

Md Ali, Siti Adlina, Maisarah Abu, and Siti Normi Zabri. "Spectrum Absorbency of Metamaterial Perfect Absorber." International Journal of Integrated Engineering 14, no. 1 (March 7, 2022). http://dx.doi.org/10.30880/ijie.2022.14.01.019.

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A triple-band metamaterial perfect absorber was introduced. The single and simple structure based on gold-bar shaped was designed on the 0.018λ Taconic TLY-5. The gold-bar shaped was designed horizontal initially was then being rotated anti-clockwise from0oto 90oto analyze and understand the change of absorption graph. Dual-band perfect metamaterial absorber was achieved at 45o. The fundamental and third harmonic magnetic resonances caused the low and high frequency peaks, respectively. Then, the gold-bar shaped was slotted at both end to create triple-band metamaterial perfect absorber. The slotted gold-bar shaped was evaluated in three absorption peaks: 99.94%, 99.88% and 99.66% at 3.98 GHz, 4.81 GHz and 5.33 GHz, respectively. This, however, moved to the 3.96 GHz, 4.80 GHz and 5.33 GHz with absorbency 99.79%, 99.95% and 99.90% for the measured structure. Both simulated and measure results were achieved absorbency over 99%, which was almost perfect absorption (≈100%). These properties are expected to beused in real-world applications such as satellite and radar communications transmission, particularly in lowering radar cross-section for stealth applications.

Статті в журналах з теми "Perfect transmission resonances"

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