scholarly journals High-precision small-scale laser focal spot measurements

2013 ◽  
Vol 31 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Z.W. Lu ◽  
X.Y. Liu ◽  
X. Wang ◽  
D.X. Ba ◽  
Z.H. Jiang ◽  
...  
Keyword(s):  
Background Noise ◽  
Measurement Accuracy ◽  
Focal Spot ◽  
Small Scale ◽  
Two Dimensional ◽  
Charge Coupled Device ◽  
Spot Diameter ◽  
Focal Spot Diameter ◽  
Laser Focal Spot ◽  
Better Than

AbstractIn this paper, a method of two-dimensional fine-scanning with charge coupled device has been conducted to precisely measure spatial position and intensity distribution of small-scale focal spot (diameter in microns). The measurement accuracy of the small-scale focal spot position is better than 1 µm when the fluctuations of the light energy and background noise are relatively small. The theoretical analysis is consistent with the experimental results.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

Improving the efficiency of the SLM-process by adjusting the focal spot diameter of the laser beam

2021 ◽  
Vol 2021 (5) ◽  
pp. 18-23
Author(s):  
S.V. Adjamskyi ◽  
◽  
G.A. Kononenko ◽  
R.V. Podolskyi ◽  
◽  
...  
Keyword(s):  
Laser Beam ◽  
Focal Spot ◽  
Spot Diameter ◽  
Focal Spot Diameter

Diffractive phase element for shrinking focal spot diameter: Design, fabrication, and application to laser beam lithography

2001 ◽  
Vol 8 (6) ◽  
pp. 416-421
Author(s):  
Yusuke Ogura ◽  
Jun Tanida ◽  
Yoshiki Ichioka ◽  
Yoshiaki Mokuno ◽  
Katsunori Matsuoka
Keyword(s):  
Laser Beam ◽  
Focal Spot ◽  
Spot Diameter ◽  
Diffractive Phase Element ◽  
Focal Spot Diameter

scholarly journals Reflection of intense laser light from microstructured targets as a potential diagnostic of laser focus and plasma temperature

2018 ◽  
Vol 7 ◽  
Author(s):  
J. Jarrett ◽  
M. King ◽  
R. J. Gray ◽  
N. Neumann ◽  
L. Döhl ◽  
...  
Keyword(s):  
Focal Spot ◽  
Laser Light ◽  
Plasma Temperature ◽  
Regular Structure ◽  
Intense Laser ◽  
Reflected Light ◽  
Laser Focus ◽  
Speckle Patterns ◽  
Focal Spot Diameter ◽  
Laser Focal Spot

The spatial-intensity profile of light reflected during the interaction of an intense laser pulse with a microstructured target is investigated experimentally and the potential to apply this as a diagnostic of the interaction physics is explored numerically. Diffraction and speckle patterns are measured in the specularly reflected light in the cases of targets with regular groove and needle-like structures, respectively, highlighting the potential to use this as a diagnostic of the evolving plasma surface. It is shown, via ray-tracing and numerical modelling, that for a laser focal spot diameter smaller than the periodicity of the target structure, the reflected light patterns can potentially be used to diagnose the degree of plasma expansion, and by extension the local plasma temperature, at the focus of the intense laser light. The reflected patterns could also be used to diagnose the size of the laser focal spot during a high-intensity interaction when using a regular structure with known spacing.

scholarly journals Laser-induced cratering of a 3DCC material at mesoscale: Experiments and simulations

2018 ◽  
Vol 183 ◽  
pp. 01028
Author(s):  
Vincent Jaulin ◽  
David Hébert ◽  
Bertrand Aubert ◽  
Jean-Luc Rullier ◽  
Frédéric Malaise ◽  
...  
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Dynamic Behaviour ◽  
Focal Spot ◽  
Dynamic Pressure ◽  
Dynamic Strength ◽  
Mesoscopic Scale ◽  
Spot Diameter ◽  
Laser Facility ◽  
Focal Spot Diameter

This study concerns the damaging of a 3-Dimension Carbon/Carbon (3DCC) composite material under dynamic loading. Experiments were performed with a laser facility delivering energies between 13 and 40 J with 100 nanoseconds pulse duration. The focal spot diameter was 250 μm, leading to dynamic pressure up to 10 GPa. The focal spot being smaller than the size of the composite components, it allows us to study the dynamic behaviour of the material at mesoscopic scale. The dynamic process of this cratering is then investigated via 3D numerical simulations, and a Johnson-Holmquist model is proposed. It appears that comparison of simulations with experimental results is useful to identify the dynamic strength of individual components of composite materials.

scholarly journals Laser and target experiments on KrF GARPUN laser installation at FIAN

1999 ◽  
Vol 17 (1) ◽  
pp. 69-88 ◽  
Author(s):  
V.D. ZVORYKIN ◽  
I.G. LEBO
Keyword(s):  
Inertial Confinement Fusion ◽  
Focal Spot ◽  
Laser Pulses ◽  
Inertial Confinement ◽  
Power Laser ◽  
Spot Diameter ◽  
Confinement Fusion ◽  
Short Laser Pulses ◽  
Focal Spot Diameter ◽  
Laser Installation

Multistage, e-beam-pumped, 100 J-class KrF laser installation “GARPUN” is described with the emphases to high-power laser beam control and target irradiation experiments. The ablation pressures in the megabar range were measured and hydrodynamic flow was investigated both experimentally and by numerical simulations for laser intensities up to 5×1012 W/cm2, pulse duration of 100 ns, and focal spot diameter 150 μm. Graphite-diamond phase transformation under laser loading was observed by dynamic and Raman scattering methods. Some approaches to the fast ignition inertial confinement fusion, using the simultaneous amplification of long and short laser pulses in KrF drivers, are considered.

Centroid Position and Intensity Distribution Measurement of the Small-Scale Focal Spot

2013 ◽  
Vol 303-306 ◽  
pp. 344-348 ◽  
Author(s):  
Xiao Yan Liu ◽  
Zhi Wei Lu ◽  
Xin Wang ◽  
De Xin Ba
Keyword(s):  
Theoretical Analysis ◽  
Intensity Distribution ◽  
Focal Spot ◽  
Small Scale ◽  
Two Dimensional ◽  
Precise Positioning ◽  
Distribution Measurement ◽  
Centroid Position

The measurement of the centroid position of small-scale focal spot is one of the most promising technologies for small-scale focal spot precise positioning. In this report, a method of two-dimensional scanning with CCD has been conducted to measure the centroid position and the intensity distribution of the small-scale focal spot. The theoretical analysis results are given.

Micrometer accuracy method for small-scale laser focal spot centroid measurement

2015 ◽  
Vol 66 ◽  
pp. 58-62 ◽  
Author(s):  
Xiaoyan Liu ◽  
Zhiwei Lu ◽  
Xin Wang ◽  
Dexin Ba ◽  
Chengyu Zhu
Keyword(s):  
Focal Spot ◽  
Small Scale ◽  
Laser Focal Spot

scholarly journals Influences of Analog-to-Digital Conversion Accuracy and Response Uniformity of CCD on Small-Scale Laser Focal Spot Measurements

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xiaoyan Liu ◽  
Dexin Ba ◽  
Deqiang Jiao ◽  
Xiangxin Shao ◽  
Xin Mu ◽  
...  
Keyword(s):  
Measurement Error ◽  
Focal Spot ◽  
Gaussian Function ◽  
Maximum Error ◽  
Small Scale ◽  
Effective Solution ◽  
Digital Conversion ◽  
Analog To Digital ◽  
Analog To Digital Conversion ◽  
Laser Focal Spot

The two-dimensional snake scanning of the CCD method provides an effective solution to measure small-scale light spots which are smaller than one CCD pixel. The influences of the A/D conversion digits and response uniformity of the CCD on the measurement error are studied. When the A/D conversion digit is 20, the measurement error can be ignored. The maximum error value of the nonuniform response of the CCD pixel when the order of the super-Gaussian function is 10 is 0.7 μm. The research results can be used to guide the experiment.

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