scholarly journals Toward the capacity limit of 2D planar Jones matrix with a single-layer metasurface

2021 ◽  
Vol 7 (25) ◽  
pp. eabh0365
Author(s):  
Yanjun Bao ◽  
Long Wen ◽  
Qin Chen ◽  
Cheng-Wei Qiu ◽  
Baojun Li
Keyword(s):  
Degrees Of Freedom ◽  
Single Layer ◽  
Planar Structure ◽  
Jones Matrix ◽  
Capacity Limit ◽  
Independent Amplitude ◽  
Arbitrary Complex ◽  
Phase Tuning ◽  
Control Light ◽  
Complex Polarization

The Jones matrix is a useful tool to deal with polarization problems, and its number of degrees of freedom (DOFs) that can be manipulated represents its polarization-controlled capabilities. A metasurface is a planar structure that can control light in a desired manner, which, however, has a limited number of controlled DOFs (≤4) in the Jones matrix. Here, we propose a metasurface design strategy to construct a Jones matrix with six DOFs, approaching the upper-limit number of a 2D planar structure. We experimentally demonstrate several polarization functionalities that can only be achieved with high (five or six) DOFs of the Jones matrix, such as polarization elements with independent amplitude and phase tuning along its fast and slow axes, triple-channel complex-amplitude holography, and triple sets of printing-hologram integrations. Our work provides a platform to design arbitrary complex polarization elements, which paves the way to a broader exploitation of polarization optics.

scholarly journals Asymmetric Diffraction in Plasmonic Meta-Gratings Using an IT-Shaped Nanoslit Array

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4097
Author(s):  
Hee-Dong Jeong ◽  
Seong-Won Moon ◽  
Seung-Yeol Lee
Keyword(s):  
Plane Wave ◽  
Periodic Structures ◽  
Single Layer ◽  
Optical Diffraction ◽  
Back Side ◽  
Infrared Band ◽  
Effective Period ◽  
Wave Nature ◽  
Control Light ◽  
Meta Atom

Diffraction is a fundamental phenomenon that reveals the wave nature of light. When a plane wave is transmitted or reflected from a grating or other periodic structures, diffracted light waves propagate at several angles that are specified by the period of the given structure. When the optical period is shorter than the wavelength, constructive interference of diffracted light rays from the subwavelength-scale grating forms a uniform plane wave. Many studies have shown that through the appropriate design of meta-atom geometry, metasurfaces can be used to control light properties. However, most semitransparent metasurfaces are designed to perform symmetric operation with regard to diffraction, meaning that light diffraction occurs identically for front- and back-side illumination. We propose a simple single-layer plasmonic metasurface that achieves asymmetric diffraction by optimizing the transmission phase from two types of nanoslits with I- and T-shaped structures. As the proposed structure is designed to have a different effective period for each observation side, it is either diffractive or nondiffractive depending on the direction of observation. The designed structure exhibits a diffraction angle of 54°, which can be further tuned by applying different period conditions. We expect the proposed asymmetric diffraction meta-grating to have great potential for the miniaturized optical diffraction control systems in the infrared band and compact optical diffraction filters for integrated optics.

Torque-Fiber-Winding (TFW)-Procedure: Manufacturing of Textile-Based Unidirectional Prepreg for Raw Material and Material Development of Carbon Fibre Reinforced Thermoplastics

2017 ◽  
Vol 742 ◽  
pp. 498-505
Author(s):  
Angelika Kolonko ◽  
Frank Helbig ◽  
Jürgen Tröltzsch ◽  
Daisy Nestler ◽  
Lothar Kroll
Keyword(s):  
Carbon Fibre ◽  
Degrees Of Freedom ◽  
Single Layer ◽  
Nonwoven Fabric ◽  
Fibre Volume ◽  
Raw Material ◽  
Laboratory Staff ◽  
Material Development ◽  
Fiber Winding ◽  
Reinforced Thermoplastics

There is the need to determine the process capability of available and novel carbon fibre (CF) roving with minimal material and reproducible procedures in the field of research and development of continuous fibre reinforced composites and structural components, as well as to identify the power delivery in thermoplastic laminate constructions. The innovative TFW procedure with the appropriate system technology allows the production of piece size variable unidirectional (UD) prepreg in a continuous sequential process of spiral winding. A flexible surface design, resulting in the partial fixation of a single highly spread CF roving on fine nonwoven fabric. By defined accumulating of composite components, the fibre volume content (FVC) is adjustable and correspond to the level of spreading and to the grammage of nonwoven fabric. Minimum single layer thickness promote compound homogeneity and thereby allow the generation of greatest possible degrees of freedom in load-oriented structural design of CF-reinforced thermoplastic lightweight products in the laboratory staff.

scholarly journals Intertwined density waves in a metallic nickelate

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Junjie Zhang ◽  
D. Phelan ◽  
A. S. Botana ◽  
Yu-Sheng Chen ◽  
Hong Zheng ◽  
...  
Keyword(s):  
Fermi Surface ◽  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Degrees Of Freedom ◽  
Density Wave ◽  
Single Layer ◽  
Late Transition Metal ◽  
Density Waves ◽  
Paramagnetic Metal ◽  
Late Transition

AbstractNickelates are a rich class of materials, ranging from insulating magnets to superconductors. But for stoichiometric materials, insulating behavior is the norm, as for most late transition metal oxides. Notable exceptions are the 3D perovskite LaNiO3, an unconventional paramagnetic metal, and the layered Ruddlesden-Popper phases R4Ni3O10, (R = La, Pr, Nd). The latter are particularly intriguing because they exhibit an unusual metal-to-metal transition. Here, we demonstrate that this transition results from an incommensurate density wave with both charge and magnetic character that lies closer in its behavior to the metallic density wave seen in chromium metal than the insulating stripes typically found in single-layer nickelates like La2-xSrxNiO4. We identify these intertwined density waves as being Fermi surface-driven, revealing a novel ordering mechanism in this nickelate that reflects a coupling among charge, spin, and lattice degrees of freedom that differs not only from the single-layer materials, but from the 3D perovskites as well.

Control of Light-Emitting Polymer Devices Using Polymer/Polymer Interfaces

1997 ◽  
Vol 488 ◽  
Author(s):  
A. J. Epstein ◽  
Y. Z. Wang ◽  
D. D. Gebler ◽  
D. K. Fu ◽  
T. M. Swager
Keyword(s):  
Reverse Bias ◽  
Forward Bias ◽  
Single Layer ◽  
Hole Transport ◽  
Cathode Side ◽  
Emeraldine Base ◽  
Polymer Interfaces ◽  
Light Emitting ◽  
Polymer Devices ◽  
Control Light

AbstractWe present the use of polymer/polymer interfaces to control light-emitting polymer devices. Bilayer devices utilizing poly(9-vinyl carbazole) (PVK) as a hole transporting/electron blocking polymer together with a pyridine containing electron transporting layer show dramatically improved efficiency and brightness as compared to single layer devices. This is attributed to charge confinement and exciplex emission at the PVK/emitting polymer interface. The introduction of emeraldine base (EB) form of polyaniline (PAN) on both side of the emitting layer enables the device to work under both forward and reverse bias, as well as in AC modes. Interfaces play an important role in the operation of these devices. Furthermore, when the EB is replaced by sulfonated polyaniline (SPAN) on the cathode side and the emitting layer is properly modified to balance electron and hole transport, the device generates different colors of light, red under forward bias and green under reverse bias.

General Beam Cross-Section Analysis Using a 3D Finite Element Slice

2014 ◽  
Author(s):  
Philippe Couturier ◽  
Steen Krenk
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Cross Sections ◽  
Degrees Of Freedom ◽  
Finite Thickness ◽  
Single Layer ◽  
Element Discretization ◽  
Cubic Polynomial ◽  
Hermitian Interpolation ◽  
Section Analysis

A formulation for analysis of general cross-section properties has been developed. This formulation is based on the stress-strain states in the classic six equilibrium modes of a beam by considering a finite thickness slice modelled by a single layer of 3D finite elements. The displacement variation in the lengthwise direction is in the form of a cubic polynomial, which is here represented by Hermitian interpolation, whereby the degrees of freedom are concentrated on the front and back faces of the slice. The theory is illustrated by application to a simple cross-section for which an analytical solution is available. The paper also shows an application to wind turbine blade cross-sections and discusses the effect of the finite element discretization on the cross-section properties such as stiffness parameters and the location of the elastic and shear centers.

scholarly journals Generalized Conditions for Hydraulic Criticality of Oceanic Overflows

2005 ◽  
Vol 35 (10) ◽  
pp. 1782-1800 ◽  
Author(s):  
Larry Pratt ◽  
Karl Helfrich
Keyword(s):  
Critical Condition ◽  
Degrees Of Freedom ◽  
Single Layer ◽  
Direct Calculation ◽  
Dissipative Systems ◽  
Hydraulic Analysis ◽  
Wave Speeds ◽  
Long Wave ◽  
Functional Formulation ◽  
Arbitrary Potential

Abstract Two methods for assessing the hydraulic criticality of an observed or modeled overflow are discussed. The methods are valid for single-layer deep flows with arbitrary potential vorticity and cross section. The first method is based on a purely steady view in which the flow at a given section is divided up into a group of “streamtubes.” A hydraulic analysis requires an extension of Gill’s functional formulation to systems with many degrees of freedom. The general form of the critical condition and associated compatibility condition for such a system are derived and applied to the streamtube model. As an aside, it is shown by example that Gill’s original critical condition can fail to capture all possible critical states, but that this problem is fixed when the multivariable approach is used. It is also shown how Gill’s method can be applied to certain dispersive or dissipative systems. The second method of assessing criticality involves direct calculation of linear, long-wave speeds using a time-dependent version of the streamtube model. This approach turns out to be better suited to the analysis of geophysical datasets. The significance of the local Froude number F is discussed. It is argued that F must take on the value unity at some point across a critical section.

scholarly journals Buckling analysis of laminated cylindrical composite shell panel under mechanical and hygrothermal loads

2005 ◽  
Vol 27 (1) ◽  
pp. 1-12
Author(s):  
Tran Ich Thinh ◽  
Le Kim Ngoc
Keyword(s):  
Deformation Theory ◽  
Degrees Of Freedom ◽  
Composite Shell ◽  
Shear Deformation Theory ◽  
Single Layer ◽  
The Finite Element Method ◽  
Isoparametric Element ◽  
Number Of Layers ◽  
Shell Panel ◽  
Cylindrical Composite Shell

This paper deals with buckling of analysis multilaminated cylindrical shell panels subjected to axial and hygrothermal loadings. The geometrical non-linear analysis is carried out using the Finite Element Method based on a single layer first shear deformation theory. A nine-nodal isoparametric element with 5 degrees of freedom per node is considered. The effects of different number of layers, lamination angles, length to width ratios and hygrothermal effects are studied.

Free Vibration Analysis of Single and Multilayered Sandwich FGM Plates-Assessment of Higher Order Refined Theories

2013 ◽  
Vol 467 ◽  
pp. 300-305 ◽  
Author(s):  
K. Swaminathan ◽  
D.T. Naveenkumar
Keyword(s):  
Shear Deformation ◽  
Transverse Shear ◽  
Degrees Of Freedom ◽  
Single Layer ◽  
Free Vibration Analysis ◽  
Higher Order ◽  
Functionally Graded ◽  
Normal Strain ◽  
Order Model ◽  
Natural Frequency Analysis

Analytical formulations and solutions for natural frequency analysis of functionally graded material (FGM) plates based on two higher-order refined shear deformation theories with 9 and 12 degrees-of-freedom are presented. The displacement model with 12 degrees-of-freedom considers the effect of both transverse shear and normal strain/stress while the other considers only the effect of transverse shear deformation. In addition another higher-order model and the first-order model developed by other investigators and available in the literature are also presented for the evaluation purpose. For mathematical modeling purposes, the Poissons ratio of the material is considered as constant whereas Youngs modulus is assumed to vary through the thickness according to the power law function. The equations of motion are derived using Hamiltons principle. Solutions are obtained in closed-form using Naviers technique and solving the eigenvalue equation. The accuracy of the theoretical formulations and the solution method using the present two higher-order refined models is first established by comparing the results generated in the present investigation with the 3D elasticity solutions already reported in the literature. After establishing the accuracy of predictions, benchmark results for the natural frequencies using all the four models are presented for single layer FGM plate and multi layered FGM sandwich plate with varying edge ratios and side-to-thickness ratios.

STATIC AND DYNAMIC BEHAVIOUR OF LAMINATED COMPOSITE BEAMS

2001 ◽  
Vol 01 (04) ◽  
pp. 545-560 ◽  
Author(s):  
M. A. RAMOS LOJA ◽  
J. INFANTE BARBOSA ◽  
C. M. MOTA SOARES
Keyword(s):  
Cross Sections ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Shear Deformation Theory ◽  
Single Layer ◽  
Laminated Composite ◽  
Element Model ◽  
Composite Beams ◽  
Straight Beam ◽  
Transverse Stresses

A higher order shear deformation theory, assuming a non-linear variation for the displacement field, is used to develop a finite element model to predict static and free vibration behaviour of anisotropic multilaminated thick and thin beams. The model is based on a single-layer Lagrangean four-node straight beam element with fourteen degrees of freedom per node. It considers bending into two orthogonal planes, stretching and twisting to enable three-dimensional analysis of frames. The most common cross sections and symmetric and asymmetric lay-ups are studied. The behaviour of the model is tested on thin and thick isotropic and composite beams. Comparisons show that the model is accurate and versatile. The good performance of the present model is evident on the prediction of displacements, normal and transverse stresses and natural frequencies of thin and thick isotropic or anisotropic beam structures.

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