scholarly journals High efficiency beam deflection by planar channeling in bent silicon crystals

2002 ◽  
Author(s):  
K. Elsener ◽  
M. Clement ◽  
N. Doble ◽  
L. Gatignon ◽  
P. Grafstrom ◽  
...  
Keyword(s):  
High Efficiency ◽  
Beam Deflection ◽  
Planar Channeling ◽  
Silicon Crystals

Investigation of Quantum States of Fast Electrons under Planar Channeling in Silicon Crystals

1987 ◽  
Vol 142 (1) ◽  
pp. 49-65 ◽  
Author(s):  
V. I. Gridnev ◽  
V. V. Kaplin ◽  
V. G. Khlabutin ◽  
E. I. Rozum ◽  
S. A. Vorobiev
Keyword(s):  
Quantum States ◽  
Planar Channeling ◽  
Fast Electrons ◽  
Silicon Crystals

Self-standing bent silicon crystals for very high efficiency Laue lens

2011 ◽  
Vol 31 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Valerio Bellucci ◽  
Riccardo Camattari ◽  
Vincenzo Guidi ◽  
Ilaria Neri ◽  
Nicolas Barrière
Keyword(s):  
High Efficiency ◽  
Silicon Crystals ◽  
Laue Lens ◽  
Very High

A Simple Co-Rotational Finite Planar Beam Element of Geometrical and Material Nonlinearity

2012 ◽  
Vol 268-270 ◽  
pp. 1163-1167
Author(s):  
Song Bai Cai ◽  
Da Zhi Li ◽  
Chang Wan Kim ◽  
Pu Sheng Shen
Keyword(s):  
Stiffness Matrix ◽  
High Efficiency ◽  
Beam Theory ◽  
Yield Function ◽  
Beam Element ◽  
Transformation Matrix ◽  
Material Nonlinearity ◽  
Beam Deflection ◽  
Nodal Force ◽  
Tangential Stiffness

A simple geometrical and material nonlinear co-rotational planar beam element of field consistency is proposed. Herein the element which produces a local stiffness matrix of 3 by 3 other than 6 by 6 is developed. Material nonlinearity is taken into account on the base of yield function of element internal forces. By applying static equilibrium relationship of classic beam theory for the transferring of local element nodal force to global element nodal force, a new transformation matrix different from the nodal displacement transformation matrix is established. Although this results in an asymmetric global tangential stiffness matrix, the new transformation is simpler, and gives rise to field consistency and makes it possible to compute very large beam deflection without remeshing of the deformed structure. Computations of numerical example indicates that formulations for the nonlinear beam element are of validation and high efficiency

scholarly journals Conditions for establishing the “generalized Snell’s law of refraction” in all-dielectric metasurfaces: theoretical bases for design of high-efficiency beam deflection metasurfaces

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Siyuan Shen ◽  
Zhaohui Ruan ◽  
Yuan Yuan ◽  
Heping Tan
Keyword(s):  
High Efficiency ◽  
Incident Light ◽  
Polarized Light ◽  
Beam Deflection ◽  
Phase Gradient ◽  
Anomalous Reflection ◽  
Snell’S Law ◽  
Polarization States ◽  
Snell's Law ◽  
The Relationship

Abstract The generalized Snell’s law dictates that introducing a phase gradient at the interface of two media can shape incident light and achieve anomalous reflection or refraction. However, when the introduced phase gradient is realized via the scattering of nanoparticles in the metasurfaces, this law needs to be modified; certain conditions need to be met when the law is established. We present the conditions for establishing the “generalized Snell’s law of refraction” in all-dielectric metasurfaces under the incidence of different polarized light. These conditions can provide theoretical bases for the subsequent design of high-efficiency beam deflection metasurfaces. The relationship between the highest achievable anomalous refraction efficiency and the number of nanoparticles within one period of the metasurface is also summarized. In addition, the generalized refraction should not depend on the polarization states of incident light; however, the previous realization conditions of anomalous refraction were sensitive to the polarization states. Thus, conditions for establishing the polarization-independent generalized Snell’s law of refraction in all-dielectric metasurfaces are presented.

scholarly journals Broadband Tunable Terahertz Beam Deflector Based on Liquid Crystals and Graphene

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1141
Author(s):  
Yanchun Shen ◽  
Jinlan Wang ◽  
Qiaolian Wang ◽  
Ximing Qiao ◽  
Yuye Wang ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
High Efficiency ◽  
Biochemical Characterization ◽  
Low Cost ◽  
Orientation Distribution ◽  
Transparent Electrode ◽  
Beam Deflection ◽  
Dynamic Tuning ◽  
Frequency Independent ◽  
Security Inspection

Terahertz (THz) technology has unique applications in, for example, wireless communication, biochemical characterization, and security inspection. However, high-efficiency, low-cost, and actively tunable THz modulators are still scarce. We propose a broadband tunable THz beam deflector based on liquid crystals (LCs). By a periodic gradual distribution of the orientation of the LC in one direction, a frequency-independent geometric phase modulation is obtained. The LC device with this specific orientation distribution was obtained through ultraviolet polarization exposure. We have verified the broadband beam deflection in both the simulation and experiment. The device can achieve a good spin-coupled beam deflection effect in the 0.8–1.2 Thz band, and the average polarization conversion efficiency exceeds 70%. Moreover, because the electro-optical responsivity of LCs is excellent, graphene transparent electrode layers introduced on the upper and lower substrates enable the deflection modulation to be switched and dynamic tuning to be achieved.

High-Efficiency Beam Deflection of Visible Light Based on Dielectric Metasurfaces

2018 ◽  
Author(s):  
Ahmmed A. Rifat ◽  
Mohsen Rahmani ◽  
Lei Xu ◽  
Khosro Zangeneh Kamali ◽  
Andrei Komar ◽  
...  
Keyword(s):  
Visible Light ◽  
High Efficiency ◽  
Beam Deflection

Microgratings for high-efficiency guided-beam deflection fabricated by electron-beam direct-writing techniques

1980 ◽  
Vol 19 (16) ◽  
pp. 2842 ◽  
Author(s):  
Y. Handa ◽  
T. Suhara ◽  
H. Nishihara ◽  
J. Koyama
Keyword(s):  
Electron Beam ◽  
High Efficiency ◽  
Beam Deflection ◽  
Direct Writing

scholarly journals Recent progress in Pancharatnam–Berry phase optical elements and the applications for virtual/augmented realities

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Yun-Han Lee ◽  
Guanjun Tan ◽  
Tao Zhan ◽  
Yishi Weng ◽  
Guigeng Liu ◽  
...  
Keyword(s):  
Recent Progress ◽  
High Efficiency ◽  
Berry Phase ◽  
Large Angle ◽  
Beam Deflection ◽  
Optical Elements ◽  
Display Devices ◽  
Head Mounted Display ◽  
Fast Switching ◽  
Display Systems

AbstractIn this review paper,we report recent progress on Pancharatnam-Berry (PB) phase optical elements, such as lens, grating, and deflector. PB lenses exhibit a fast switching time between two or more focal lengths with large diopter change and aperture size, which is particularly attractive for addressing the accommodation mismatch in head-mounted display devices. On the other hand, PB gratings and deflectors offer a large-angle beam deflection with wide acceptance cone and high efficiency, as compared to conventional volume gratings. Such merits provide great advantages for waveguide-coupling augmented reality headsets. Moreover, the thickness of PB optical elements is only a few micrometers, thus they can be conveniently integrated into modern wearable display systems.

scholarly journals All-Dielectric Huygens’ Metasurface for Wavefront Manipulation in the Visible Region

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5967
Author(s):  
Tiesheng Wu ◽  
Zhihui Liu ◽  
Weiping Cao ◽  
Huixian Zhang ◽  
Dan Yang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Visible Region ◽  
Transmission Efficiency ◽  
Unique Property ◽  
Beam Deflection ◽  
Dielectric Plate ◽  
Phase Gradient ◽  
Dipole Resonance ◽  
Operating Wavelength ◽  
Diffraction Angle

All-dielectric Huygens’ metasurfaces have been widely used in wavefront manipulation through multipole interactions. Huygens’ metasurfaces utilize the superposition between an electric dipole and a magnetic dipole resonance to realize transmission enhancement and an accumulated 2π phase change. Benefiting from this unique property, we design and numerically investigate an all-dielectric Huygens’ metasurface exhibiting high-efficiency anomalous refraction. To suppress the substrate effect, the metasurface structure is submerged in a dielectric plate. We strategically placed two elements in four short periods to form a unit cell and adjusted the spacing between the two elements to effectively inhibit the interaction between elements. At the operating wavelength of 692 nm, the obtained anomalous transmission efficiency is over 90.7% with a diffraction angle of 30.84°. The performance of the proposed structure is far superior to most of the existing phase-gradient metasurface structures in the visible region, which paves the way for designing efficient beam deflection devices.

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