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

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

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°.

scholarly journals Fused silica ablation by double femtosecond laser pulses: influence of polarization state

2020 ◽  
Vol 28 (10) ◽  
pp. 15189
Author(s):  
Kevin Gaudfrin ◽  
John Lopez ◽  
Konstantin Mishchik ◽  
Laura Gemini ◽  
Rainer Kling ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Polarization State ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Fused Silica

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.

Factors Affecting Quantitative Studies of Surface Adsorbates Using Multiresonant Second-Order Nonlinear Spectroscopy

1987 ◽  
Vol 41 (8) ◽  
pp. 1329-1335 ◽  
Author(s):  
Stephanie A. Cresswell ◽  
Jack K. Steehler
Keyword(s):  
Incidence Angle ◽  
Nile Blue ◽  
Detection Limits ◽  
Initial Study ◽  
Fused Silica ◽  
Nonlinear Spectroscopy ◽  
Cresyl Violet ◽  
Mixture Component ◽  
Quantitative Studies ◽  
Power Densities

Fundamental quantitative studies of dyes (Nile Blue 690, Oxazine 725, Cresyl Violet 670) adsorbed to fused-silica surfaces were performed to determine the usefulness of multiresonant χ(2) spectroscopy as a surface-selective tool. Factors considered include laser-induced desorption, saturation of resonant transitions, choice of the most useful molecular resonances, molecular orientation, laser incidence angle, and laser polarization. In the most restrictive case (doubly resonant), elimination of desorption and saturation problems required laser power densities below 67 kW/cm2, while for a nonresonant case power densities of 2 GW/cm2 could be used. The resonant enhancement of χ(2) and limitations on usable power densities combine to yield similar detection limits for resonant and nonresonant studies. Detection limits of 0.037 to 0.17 monolayer were obtained for various multiresonant and nonresonant cases. The multiresonant case retains the important advantage of selecting a single mixture component for examination, as demonstrated by an initial study of an adsorbate mixture system.

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).

SEM analysis of DC magnetron sputtered beryllium films

1988 ◽  
Vol 46 ◽  
pp. 960-961
Author(s):  
E. F. Lindsey ◽  
C. W. Price ◽  
E. L. Pierce ◽  
E. J. Hsieh
Keyword(s):  
Fine Structure ◽  
Electron Emission ◽  
Secondary Electron ◽  
Low Voltage ◽  
Ion Beam ◽  
Secondary Electron Emission ◽  
Sem Analysis ◽  
Fused Silica ◽  
Grain Structure ◽  
Silica Substrate

Columnar structures produced by DC magnetron sputtering can be altered by using RF biased sputtering or by exposing the film to nitrogen pulses during sputtering, and these techniques are being evaluated to refine the grain structure in sputtered beryllium films deposited on fused silica substrates. Beryllium is brittle, and fractures in sputtered beryllium films tend to be intergranular; therefore, a convenient technique to analyze grain structure in these films is to fracture the coated specimens and examine them in an SEM. However, fine structure in sputtered deposits is difficult to image in an SEM, and both the low density and the low secondary electron emission coefficient of beryllium seriously compound this problem. Secondary electron emission can be improved by coating beryllium with Au or Au-Pd, and coating also was required to overcome severe charging of the fused silica substrate even at low voltage. The coating structure can obliterate much of the fine structure in beryllium films, but reasonable results were obtained by using the high-resolution capability of an Hitachi S-800 SEM and either ion-beam coating with Au-Pd or carbon coating by thermal evaporation.

Sign in / Sign up

Export Citation Format

Share Document