Analysis of spatial coherence length of high harmonic generated in argon

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Nor Azah Abdul Aziz ◽  
Emma Ziezie Mohd Tarmizi ◽  
Khuong Ba Dinh
Keyword(s):  
Coherence Length ◽  
High Harmonic ◽  
Spatial Coherence

Extraordinary Coherent Thermal Emission From SiC Due to Coupled Resonant Cavities

2008 ◽  
Vol 130 (11) ◽  
Author(s):  
Nir Dahan ◽  
Avi Niv ◽  
Gabriel Biener ◽  
Yuri Gorodetski ◽  
Vladimir Kleiner ◽  
...  
Keyword(s):  
Quality Factor ◽  
Coherence Length ◽  
Thermal Emission ◽  
Spatial Coherence ◽  
Optical Filters ◽  
High Quality Factor ◽  
Experimental Results ◽  
Thermal Source ◽  
High Quality ◽  
Resonant Cavities

In high temperature and vacuum applications, when heat transfer is predominantly by radiation, the material’s surface texture is of substantial importance. Several micro- and nanostructure designs have been proposed to enhance a material’s emissivity and its radiative coherence, as control of thermal emission is of crucial concern in the design of infrared sources, optical filters, and sensing devices. In this research, an extraordinary coherent thermal emission from an anisotropic microstructure is experimentally and theoretically presented. The enhanced coherency is due to coherent coupling between resonant cavities obtained by surface standing waves, wherein each cavity supports a localized field that is attributed to coupled surface phonon polaritons. We show that it is possible to obtain a polarized quasimonochromatic thermal source from a SiC microstructure with a high quality factor of 600 at the resonant frequency of the cavity and a spatial coherence length of 716 wavelengths, which corresponds to an angular divergence of 1.4mrad. In the experimental results, we measured a quality factor of 200 and a spatial coherence length of 143 wavelengths. We attribute the deviation in the experimental results to imperfections in the fabrication of the high quality factor cavities.

scholarly journals Measuring and structuring the spatial coherence length of organic light-emitting diodes

2015 ◽  
Vol 10 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Guohua Xie ◽  
Mingzhou Chen ◽  
Michael Mazilu ◽  
Shuyu Zhang ◽  
A.K. Bansal ◽  
...  
Keyword(s):  
Coherence Length ◽  
Light Emitting Diodes ◽  
Spatial Coherence ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light

Effect of the spatial coherence length on the self-reconfiguration of a speckle field

2016 ◽  
Vol 94 (1) ◽  
Author(s):  
Cleberson R. Alves ◽  
Alcenísio J. Jesus-Silva ◽  
Eduardo J. S. Fonseca
Keyword(s):  
Coherence Length ◽  
Spatial Coherence ◽  
The Self ◽  
Speckle Field

Effect of finite spatial coherence length on small-angle scattering

2015 ◽  
Vol 48 (6) ◽  
pp. 1660-1664 ◽  
Author(s):  
Yuya Shinohara ◽  
Yoshiyuki Amemiya
Keyword(s):  
Small Angle ◽  
Coherence Length ◽  
Spatial Coherence ◽  
Small Angle Scattering ◽  
Forward Scattering ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Imaging ◽  
Angle Scattering ◽  
Diffraction Imaging

This study shows that forward scattering at the origin of reciprocal space contributes to the scattering intensity profiles of ultra-small-angle scattering. The forward scattering corresponds to a Fourier transform of the X-ray coherent volume on a sample. This contribution is usually ignored in the study of small-angle scattering, while it is fully considered in the fields of X-ray imaging, such as coherent X-ray diffraction imaging and X-ray ptychography. This effect is explicitly illustrated in the context of small-angle scattering, and the effect of a finite spatial coherence length on small-angle scattering is discussed.

scholarly journals Transverse horizontal spatial coherence in shallow water

2019 ◽  
Vol 283 ◽  
pp. 02001
Author(s):  
Bo Zhang ◽  
Fenghua Li ◽  
Zhenglin Li ◽  
Yanjun Zhang ◽  
Jingyan Wang
Keyword(s):  
Shallow Water ◽  
Acoustical Society ◽  
Coherence Length ◽  
Environmental Variability ◽  
Northern South China Sea ◽  
Spatial Coherence ◽  
Normal Modes ◽  
Sound Field ◽  
Acoustic Frequency ◽  
Field Correlation

Since the advent of large-aperture array processing, more and more attention has been paid to the sound field correlation, which has fundamental limit to the array gain of spatial coherent signal processing. The two dominant mechanisms that degrade the spatial coherence are normal modes (or multi-paths) interference and the environmental variability caused by several relevant oceanographic processes. In the present study, the transverse horizontal spatial coherence of explosive signals has been studied experimentally by a bottom-mounted array in the Northern South China Sea. And the effects of normal mode interference on the transverse horizontal spatial coherence have been analyzed numerically. Expressed in terms of wavelengths, the coherence length is shown to be larger than 170λ/185λ at acoustic frequency 508-640Hz/80-101Hz in shallow water. It is much greater than Carey’s shallow-water result 30λ estimated from array signal gain after assuming a specific functional form for the coherence (The Journal of the Acoustical Society of America 104, 831 (1998)). It, however, is consistent with Rouseff’s modelling result of a coherence length larger than 100λ (The Journal of the Acoustical Society of America 138, 2256 (2015)). Both Carey and Rouseff argue that the transverse horizontal spatial coherence length depends only weakly on range, in direct. In the present study, however, the coherence length is shown to depend highly on source-receiver range, and it fluctuates synchronously with the sound-field intensity while range varies.

scholarly journals Research on the propagation of partially coherent cosh-Gaussian beams through an ABCD optical system in non-Kolmogorov turbulence by effective tensor approach

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Hongjie Ma ◽  
Jinsong Li ◽  
Yueyang Chen
Keyword(s):  
Optical System ◽  
Coherence Length ◽  
Spatial Coherence ◽  
Structure Constant ◽  
Beam Propagation ◽  
Gaussian Beams ◽  
Average Intensity ◽  
Partially Coherent ◽  
Kolmogorov Turbulence ◽  
Abcd Optical System

An efficient tensor approach is used to study the propagation of partially coherent cosh-Gaussian beams through an ABCD optical system in non-Kolmogorov turbulence. Analytical expressions for the average intensity of the beam propagation are derived. The properties of the average intensity are investigated with a numerical example. One finds that the propagation of the beam with larger spatial coherence length is less affected by distance when the propagation distance is long enough, and as the Ch-parameter increases, the beam propagation is less effected by turbulent atmosphere. It is also found that the average intensity distribution of the cosh-Gaussian beams with larger spatial correlation length is more affected by the structure constant of turbulence (i.e., turbulence level). By choosing a suitable Ch-parameter and spatial coherence length, the partially coherent cosh-Gaussian beams can be better transmitted in non-Kolmogorov turbulence. Our results will be useful in free-space communication.

Rocking curve and spatial coherence properties of a long X-ray compound refractive lens

2018 ◽  
Vol 25 (6) ◽  
pp. 1634-1641 ◽  
Author(s):  
V. G. Kohn
Keyword(s):  
Coherence Length ◽  
Recurrence Relations ◽  
Spatial Coherence ◽  
Incident Radiation ◽  
Source Size ◽  
Beam Size ◽  
Angular Divergence ◽  
Rocking Curve ◽  
X Ray ◽  
Minimal Difference

Semi-analytical theory of a long set of X-ray compound refractive lenses (CRLs) based on recurrence relations is developed further. The geometrical aperture, angular divergence of incident radiation and source size were accurately taken into account. Using this theory it is possible to calculate the width of the rocking curve of a long (40.7 cm) Be CRL which coincides with experimental data obtained earlier. By this approach the transverse coherence length for the X-ray beam after passing a set of CRLs of arbitrary complexity has been estimated. It is shown that at the focus this coherence length is equal to a diffraction-limited beam size (beam size in the case of a point source) and has minimal difference with the real beam size.

scholarly journals Soft-mode of charged chiral fibrous viruses (fd)

Soft Matter ◽  
2016 ◽  
Vol 12 (30) ◽  
pp. 6385-6399 ◽  
Author(s):  
Kyongok Kang
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Small Angle ◽  
Coherence Length ◽  
Soft Mode ◽  
Spatial Coherence ◽  
Repulsive Forces ◽  
Microscopic Dynamics

From microscopic dynamics of charged chiral fd-viruses, the soft-mode is revealed with a rotation restoring “twist”, obtained from both polarized (VV) and depolarized (VH) small angle dynamic light scattering. Here, I have found the minimum spatial coherence length at a lower I–N binodal concentration, which is due to the reverse of electrostatic repulsive forces with an increase in the concentration of charged chiral rods.

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