scholarly journals Reflection Characteristics of Airy Beams Impinging on Graphene-Substrate Surfaces

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Fuping Wu ◽  
Yuanfei Hui ◽  
Zhiwei Cui ◽  
Ju Wang
Keyword(s):  
Precise Measurement ◽  
Incident Angle ◽  
Strong Dependence ◽  
Polarization State ◽  
Potential Applications ◽  
Beam Parameters ◽  
Substrate Surfaces ◽  
Analytical Expressions ◽  
Reflection Characteristics ◽  
Airy Beams

In this work, we analytically and numerically investigate the reflection characteristics of the airy beams impinging on graphene-substrate surfaces. The explicit analytical expressions for the electric and magnetic field components of the airy beams reflected from a graphene-substrate interface are derived. The local-field amplitude, Poynting vector, and spin and orbital angular momentum of the reflected airy beams with different graphene structure and beam parameters are presented and discussed. The results show that the reflection properties of the airy beams can be flexibly tuned by modulating the Fermi energy of the graphene and have a strong dependence on the incident angle and polarization state. These results may have potential applications in the modulation of airy beams and precise measurement of graphene structure parameters.

scholarly journals Achromatic terahertz Airy beam generation with dielectric metasurfaces

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Qingqing Cheng ◽  
Juncheng Wang ◽  
Ling Ma ◽  
Zhixiong Shen ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Biomedical Imaging ◽  
Frequency Dispersion ◽  
Light Sheet ◽  
Photonic Devices ◽  
Self Healing ◽  
Beam Focusing ◽  
Light Sheet Microscopy ◽  
Airy Beam ◽  
Potential Applications ◽  
Airy Beams

AbstractAiry beams exhibit intriguing properties such as nonspreading, self-bending, and self-healing and have attracted considerable recent interest because of their many potential applications in photonics, such as to beam focusing, light-sheet microscopy, and biomedical imaging. However, previous approaches to generate Airy beams using photonic structures have suffered from severe chromatic problems arising from strong frequency dispersion of the scatterers. Here, we design and fabricate a metasurface composed of silicon posts for the frequency range 0.4–0.8 THz in transmission mode, and we experimentally demonstrate achromatic Airy beams exhibiting autofocusing properties. We further show numerically that a generated achromatic Airy-beam-based metalens exhibits self-healing properties that are immune to scattering by particles and that it also possesses a larger depth of focus than a traditional metalens. Our results pave the way to the realization of flat photonic devices for applications to noninvasive biomedical imaging and light-sheet microscopy, and we provide a numerical demonstration of a device protocol.

Anomalous transport of light at the phase transition to localization: strong dependence with incident angle

2018 ◽  
Vol 6 (10) ◽  
pp. 929 ◽  
Author(s):  
Ernesto Jimenez-Villar ◽  
M. C. S. Xavier ◽  
Niklaus U. Wetter ◽  
Valdeci Mestre ◽  
Weliton S. Martins ◽  
...  
Keyword(s):  
Phase Transition ◽  
Incident Angle ◽  
Strong Dependence ◽  
Anomalous Transport

scholarly journals Polarization-Independent Metasurface Lens Based on Binary Phase Fresnel Zone Plate

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1467
Author(s):  
Xing Li ◽  
Jing Tang ◽  
Jonathan Baine
Keyword(s):  
Fresnel Zone ◽  
Incident Light ◽  
Polarization State ◽  
Zone Plate ◽  
Visible Range ◽  
Fresnel Zone Plate ◽  
Binary Phase ◽  
Nanophotonic Devices ◽  
Potential Applications ◽  
Polarization Independent

Based on the binary phase Fresnel zone plate (FZP), a polarization-independent metasurface lens that is able to focus incident light with any polarization state, including circular, linear, and elliptical polarizations, has been proposed and investigated. We demonstrate that the metasurface lens consisting of metal subwavelength slits can operate in a wide bandwidth in the visible range, and has a higher focusing efficiency than that of an amplitude FZP lens without phase modulation. A multi-focus FZP metasurface lens has also been designed and investigated. The proposed lens can provide potential applications in integrated nanophotonic devices without polarization limitations.

scholarly journals Reconfigurable honeycomb metamaterial absorber having incident angular stability

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Javad Shabanpour ◽  
Sina Beyraghi ◽  
Homayoon Oraizi
Keyword(s):  
Electromagnetic Interference ◽  
Oblique Incidence ◽  
Mechanical Performance ◽  
Incident Angle ◽  
Normal Incidence ◽  
Metallic Phase ◽  
Metamaterial Absorber ◽  
Angular Stability ◽  
Ohmic Losses ◽  
Potential Applications

Abstract Ultrawide-angle electromagnetic wave absorbers with excellent mechanical properties are required in many diverse applications such as sensing, and stealth technologies. Here, a novel 3D reconfigurable metamaterial absorber (MMA) consisting of honeycomb and VO2 films is proposed. The proposed MMA exhibits a strong absorptivity above 90% in the widest incident angle up to $$87^\circ $$ 87 ∘ for TM- and TE polarized oblique incidences for THz wave propagating in yoz-plane. Under normal incidence, when VO2 films are in the insulating state, the proposed absorber exhibits high absorptivity in the frequency band of 1–4 THz. By increasing the temperature of the whole structure, the structural transformation of VO2 occurs and turns into the metallic phase. We have shown that under oblique incidence, the ohmic losses of VO2 films especially those parallel to the direction of the incident electric field are the most important absorption principles of the proposed MMA. Due to the ultra wide-angle absorption (angular stability) and mechanical performance, it is expected that the presented MMA may find potential applications, such as camouflage technologies, electromagnetic interference, imaging, and sensing. To the best knowledge of authors, the proposed MMA configuration exhibits the absorptivity in the widest incident angle ever reported.

New conductive IBAD buffer for HTS applications

2001 ◽  
Vol 689 ◽  
Author(s):  
Karola Thiele ◽  
Sibylle Sievers ◽  
Juergen Dzick ◽  
Lars-Oliver Kautschor ◽  
Christian Jooss ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Film Growth ◽  
Incident Angle ◽  
Texture Evolution ◽  
Ion Beam ◽  
Buffer Layers ◽  
Electrically Conductive ◽  
Ito Thin Films ◽  
Beam Parameters

ABSTRACTBiaxially aligned Indium Tin Oxide (ITO) thin films to be used as electrically conductive buffer layers were prepared by an Ion-Beam Assisted Deposition (IBAD) process on various substrates. Two Kaufman ion sources with 2.5 cm diameter were employed for the assisting and the sputtering beam, respectively. All deposited films revealed (001) oriented film growth with a strong in-plane alignment. The degree of the in-plane orientation was studied depending on the ion-beam parameters and the incident angle. Investigations (TEM and X-ray) of the texture evolution of these IBAD films during film growth were carried out. An in-plane texture of 12.6°FWHM for a 1 μm thick film has been achieved so far. The quality of the buffer has been demonstrated by the subsequent deposition of high-current carrying YBCO-films deposited by thermal coevaporation using a 3–5 nm thick Y2O3 interlayer. A jc of 0.76 MA/cm2 (77K, 0T) has been obtained for a 1 cm × 1 cm sample with ITO of 20° FWHM.

MANIPULATING THE POLARIZATION OF TERAHERTZ WAVES WITH METAMATERIAL DEVICES

2014 ◽  
Vol 02 (02) ◽  
pp. 1440008 ◽  
Author(s):  
LONGQING CONG ◽  
JIANQIANG GU ◽  
ZHEN TIAN ◽  
RANJAN SINGH ◽  
JIAGUANG HAN ◽  
...  
Keyword(s):  
Polarization State ◽  
Terahertz Waves ◽  
Optical Components ◽  
Polarization Control ◽  
Design Flexibility ◽  
Potential Applications ◽  
Excellent Control ◽  
Terahertz Frequencies ◽  
Control Devices ◽  
Increasing Demand

As the potential applications of terahertz science and technology become extremely important, there is an increasing demand for improved terahertz optical components. One of such devices on demand is the class of polarization control devices. Recently, metasurfaces have emerged as designer structures with excellent control, design flexibility, and multifaceted functionalities. Metamaterials offer fascinating prospects for manipulating the polarization state of terahertz waves. Here, we discuss different metamaterial device designs that exhibit properties of perfect linear polarization rotation and linear to either linear or circular polarization conversion at narrowband as well as broadband terahertz frequencies.

scholarly journals Wideband and Large Angle Electromagnetically Induced Transparency by the Equivalent Transmission Line in a Metasurface

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Renxia Ning ◽  
Dekai Li ◽  
Tianlong Yang ◽  
Zhenhai Chen ◽  
Hongwen Qian
Keyword(s):  
Time Domain ◽  
Symmetry Axis ◽  
Electromagnetically Induced Transparency ◽  
Incident Angle ◽  
Large Angle ◽  
Integration Time ◽  
Main Structure ◽  
Potential Applications ◽  
Equivalent Circuit Method ◽  
Induced Transparency

Abstract A classical structure for a U-shaped metasurface exhibiting a wideband and large angle electromagnetically induced transparency (EIT) effect in the terahertz range is proposed. One horizontal and two vertical strips, which represent the bright and dark modes, respectively, are created for the U-shaped structure. The finite integration time domain (FITD) and equivalent circuit method are compared with the EIT result. The EIT effect is affected by the length of the vertical bar and by the distance from the vertical bar to the symmetry axis. The results show that the asymmetry of the main structure in the x and y axes makes it easier to achieve the EIT effect. In addition, by changing the incident angle, the EIT effect always exists until the angle of the incidental electromagnetic wave is 85 degrees. These results have many potential applications for terahertz filtering, large-angle switching and sensors.

Transmission characteristics of terahertz Bessel vortex beams through a multi-layered anisotropic magnetized plasma slab

2021 ◽  
Author(s):  
Haiying Li ◽  
Jiachen Tong ◽  
Wei Ding ◽  
Bing Xu ◽  
Lu Bai
Keyword(s):  
Magnetic Field ◽  
Plasma Density ◽  
Applied Magnetic Field ◽  
Incident Angle ◽  
Polarization State ◽  
Major Effect ◽  
Magnetized Plasma ◽  
Transmitted Beam ◽  
Plasma Slab ◽  
Vortex Beams

Abstract The transmission of terahertz (THz) Bessel vortex beams through a multi-layered anisotropic magnetized plasma slab is investigated by using a hybrid method of cylindrical vector wave functions (CVWFs) and Fourier transform. On the basis of the electromagnetic boundary conditions on each interface, a cascade form of expansion coefficients of the reflected and transmitted fields is obtained. Taking a double Gaussian distribution of the plasma density as an example, the influences of the applied magnetic field, the incident angle and polarization mode of the incident beams on the magnitude, OAM mode and polarization of the transmitted beams are analyzed in detail. The results indicate that the applied magnetic field has a major effect upon the polarization state of the transmitted fields but not upon the transmitted OAM spectrum. The incident angle has a powerful influence upon both the amplitude profile and the OAM spectrum of the transmitted beam. Furthermore, for multiple coaxial vortex beams, an increase of the maximum value of the plasma density causes more remarkable distortion of both the profile and OAM spectrum of the transmitted beam. This research makes a stable foundation for the THz OAM multiplexing/demultiplexing technology in magnetized plasma environment.

scholarly journals Dual-Focuses Metalens for Copolarized and Cross-Polarized Transmission Waves

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ru Ji ◽  
Kejian Chen ◽  
Yujie Ni ◽  
Yanan Hua ◽  
Kaiwen Long ◽  
...  
Keyword(s):  
Polarization State ◽  
Phase Region ◽  
Imaging Systems ◽  
Orthogonal Polarization ◽  
Frequency Range ◽  
Orthogonal Direction ◽  
Resonator Structure ◽  
Terahertz Communications ◽  
Phase Profile ◽  
Potential Applications

Metasurfaces can reshape the wavefront in the desired manner by manipulating the phase profile and amplitude of the incident wave. In this paper, we demonstrate an ultrathin terahertz metalens based on our designed resonator structure, where the polarization state can be converted to the orthogonal direction and the parabolic phase profile is designed covering a 2π phase region. Many functional metalenses are also engineered to meet the demand of focusing, dual-polarization confocal, and dual focuses for orthogonal polarization in the frequency range from 0.65 to 0.8 THz. The presented metalenses can provide potential applications in terahertz communications and imaging systems.

Applications of the Theory of Optical Spectroscopy to Numerical Simulations

1993 ◽  
Vol 47 (5) ◽  
pp. 566-574 ◽  
Author(s):  
M. Milosevic ◽  
S. L. Berets
Keyword(s):  
Experimental Data ◽  
Optical Constants ◽  
Incident Angle ◽  
Spectroscopic Technique ◽  
Sample Thickness ◽  
Spectroscopic Techniques ◽  
Spectral Features ◽  
Reflection Spectra ◽  
Experimental Conditions ◽  
Potential Applications

A numerical simulation has been developed to extract the optical constants from experimental spectra. In particular, transmission, internal reflection, and external reflection spectra can be simulated for any incident angle, polarization, and sample thickness. The simulation is used here to determine the optical constants of two materials and to illustrate differences in spectral features that arise from variations in experimental conditions. Other potential applications of this method include determining film thicknesses from experimental data, selecting the best spectroscopic technique for a particular sample, and cross-referencing spectroscopic techniques.

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