Measurement of the dispersion properties of large aperture mirrors at arbitrary incidence angle and polarization state

2018 ◽  
Author(s):  
Máté Kovács ◽  
Tamás Somoskoi ◽  
Imre Seres ◽  
Adam Börzsönyi ◽  
Áron Sipos
Keyword(s):  
Incidence Angle ◽  
Polarization State ◽  
Dispersion Properties ◽  
Large Aperture

scholarly journals Polarization-selective modulation of supercavity resonances originating from bound states in the continuum

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Chan Kyaw ◽  
Riad Yahiaoui ◽  
Joshua A. Burrow ◽  
Viet Tran ◽  
Kyron Keelen ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Bound States ◽  
Photonic Band Gap ◽  
Incidence Angle ◽  
Polarization State ◽  
Normal Incidence ◽  
Polarization Angle ◽  
Sensing Applications ◽  
Symmetry Protected ◽  
The Continuum

AbstractBound states in the continuum (BICs) are widely studied for their ability to confine light, produce sharp resonances for sensing applications and serve as avenues for lasing action with topological characteristics. Primarily, the formation of BICs in periodic photonic band gap structures are driven by symmetry incompatibility; structural manipulation or variation of incidence angle from incoming light. In this work, we report two modalities for driving the formation of BICs in terahertz metasurfaces. At normal incidence, we experimentally confirm polarization driven symmetry-protected BICs by the variation of the linear polarization state of light. In addition, we demonstrate through strong coupling of two radiative modes the formation of capacitively-driven Freidrich-Wintgen BICs, exotic modes which occur in off-Γ points not accessible by symmetry-protected BICs. The capacitance-mediated strong coupling at 0° polarization is verified to have a normalized coupling strength ratio of 4.17% obtained by the Jaynes-Cummings model. Furthermore, when the polarization angle is varied from 0° to 90° (0° ≤ ϕ < 90°), the Freidrich-Wintgen BIC is modulated until it is completely switched off at 90°.

Influence of incidence angle and polarization state on the damage site characteristics of fused silica

2013 ◽  
Vol 53 (4) ◽  
pp. A96 ◽  
Author(s):  
Bin Ma ◽  
Yanyun Zhang ◽  
Hongping Ma ◽  
Hongfei Jiao ◽  
Xinbin Cheng ◽  
...  
Keyword(s):  
Incidence Angle ◽  
Polarization State ◽  
Fused Silica ◽  
Damage Site ◽  
Site Characteristics

Microstructural Identification of SiNx Films by Real-Time Ellipsometry

1997 ◽  
Vol 472 ◽  
Author(s):  
G. Soto ◽  
E. C. Samano ◽  
R. Machorro ◽  
M. Avalos ◽  
L. Cota
Keyword(s):  
Real Time ◽  
Film Growth ◽  
Incidence Angle ◽  
Polarization State ◽  
Sample Surface ◽  
Deposition Process ◽  
Slight Variation ◽  
Si Substrates ◽  
Amorphous Si

ABSTRACTReal-time ellipsometry has shown to be a powerful tool to analyze thin films during processing. It is non-disturbing and its sensitivity lies in the submonolayer range. In fact, a slight variation in the film microstructure might result in a significant change of the polarization state of the reflected beam from the sample surface. SiNx layers have been grown on glass, quartz, KC1 and Si substrates by laser ablating a Si3N4 sintered target in vacuum and N2 environment. The film growth was monitored by real time ellipsometry at a fixed wavelength, and a fixed incidence angle. Once the deposition process is completed, the refractive index was obtained by perfoming in situ spectroellipsometric measurements in the 1.5 to 5 eV photon-energy range. The best curve fitting of the experimental data is used to find the film composition: a mixture of Si3N4, polycrystalline Si, and amorphous Si. The films composition and micro structure inferred from ellipsometric data are compared to those obtained by in-situ surface techniques and TEM, respectively.

A tailored ultra-broadband electromagnetically induced transparency metamaterial based on graphene

2021 ◽  
Author(s):  
Fenying Li ◽  
Tao Zhang ◽  
Quan-Fang Chen ◽  
Haining Ye ◽  
Xinlei Zhang ◽  
...  
Keyword(s):  
Slow Light ◽  
Electromagnetically Induced Transparency ◽  
Incidence Angle ◽  
Polarization State ◽  
Optical Switches ◽  
Optical Modulators ◽  
Low Loss ◽  
Wave Effect ◽  
Loss Index ◽  
Induced Transparency

Abstract Based on graphene, an ultra-broadband electromagnetically induced transparency (EIT) window with dynamic tunability is realized in theory. Through altering the Fermi level of graphene that can be regulated by the external voltage, the EIT window and the EIT effect, especially the slow-wave effect, can be easily adjusted. Moreover, the bandwidth of the EIT window can be changed by the incidence angle, achieving the transformation from broadband to narrowband. At the same time, by discussing the polarization state and loss index, the characteristics of polarization insensitivity and low loss are proved. Additionally, the influences of other parameters are discussed, such as the relaxation time of graphene and coupling distance. These unique features enable the designed EIT metamaterial to be masterly applied to optical switches, optical modulators, and slow-light devices.

The influence of incidence angle and polarization state on the damaged sites characteristics of fused silica

2013 ◽  
Author(s):  
Bin Ma ◽  
Yanyun Zhang ◽  
Hongping Ma ◽  
Hongfei Jiao ◽  
Xinbin Cheng ◽  
...  
Keyword(s):  
Incidence Angle ◽  
Polarization State ◽  
Fused Silica

Electron Channeling Patterns

1977 ◽  
Vol 35 ◽  
pp. 12-13
Author(s):  
David C. Joy
Keyword(s):  
Electron Diffraction ◽  
Incidence Angle ◽  
Photographic Plate ◽  
Diffraction Effect ◽  
Angle Of Incidence ◽  
Bulk Single Crystal ◽  
Time Resolved ◽  
Electron Channeling ◽  
Spatially Resolved ◽  
Large Bulk

Electron channeling patterns (ECP) were first found by Coates (1967) while observing a large bulk, single crystal of silicon in a scanning electron microscope. The geometric pattern visible was shown to be produced as a result of the changes in the angle of incidence, between the beam and the specimen surface normal, which occur when the sample is examined at low magnification (Booker, Shaw, Whelan and Hirsch 1967).A conventional electron diffraction pattern consists of an angularly resolved intensity distribution in space which may be directly viewed on a fluorescent screen or recorded on a photographic plate. An ECP, on the other hand, is produced as the result of changes in the signal collected by a suitable electron detector as the incidence angle is varied. If an integrating detector is used, or if the beam traverses the surface at a fixed angle, then no channeling contrast will be observed. The ECP is thus a time resolved electron diffraction effect. It can therefore be related to spatially resolved diffraction phenomena by an application of the concepts of reciprocity (Cowley 1969).

Atomic force microscopy (AFM) of the topography of silicon surfaces exposed to ion beams

1992 ◽  
Vol 50 (2) ◽  
pp. 1132-1133
Author(s):  
Mark Denker ◽  
Jennifer Wall ◽  
Mark Ray ◽  
Richard Linton
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Incidence Angle ◽  
Ion Beam ◽  
Depth Profiling ◽  
Depth Resolution ◽  
Ion Beams ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Trace Impurities ◽  
Energy Dose

Reactive ion beams such as O2+ and Cs+ are used in Secondary Ion Mass Spectrometry (SIMS) to analyze solids for trace impurities. Primary beam properties such as energy, dose, and incidence angle can be systematically varied to optimize depth resolution versus sensitivity tradeoffs for a given SIMS depth profiling application. However, it is generally observed that the sputtering process causes surface roughening, typically represented by nanometer-sized features such as cones, pits, pyramids, and ripples. A roughened surface will degrade the depth resolution of the SIMS data. The purpose of this study is to examine the relationship of the roughness of the surface to the primary ion beam energy, dose, and incidence angle. AFM offers the ability to quantitatively probe this surface roughness. For the initial investigations, the sample chosen was <100> silicon, and the ion beam was O2+.Work to date by other researchers typically employed Scanning Tunneling Microscopy (STM) to probe the surface topography.

Principle and practice of high-resolution imaging with a field-emission TEM

1992 ◽  
Vol 50 (1) ◽  
pp. 138-139
Author(s):  
Max T. Otten ◽  
Wim M.J. Coene
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Incidence Angle ◽  
Temporal Coherence ◽  
Energy Spread ◽  
High Resolution Imaging ◽  
Major Improvement ◽  
High Resolution Images ◽  
Resolution Imaging

High-resolution imaging with a LaB6 instrument is limited by the spatial and temporal coherence, with little contrast remaining beyond the point resolution. A Field Emission Gun (FEG) reduces the incidence angle by a factor 5 to 10 and the energy spread by 2 to 3. Since the incidence angle is the dominant limitation for LaB6 the FEG provides a major improvement in contrast transfer, reducing the information limit to roughly one half of the point resolution. The strong improvement, predicted from high-resolution theory, can be seen readily in diffractograms (Fig. 1) and high-resolution images (Fig. 2). Even if the information in the image is limited deliberately to the point resolution by using an objective aperture, the improved contrast transfer close to the point resolution (Fig. 1) is already worthwhile.

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