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

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.

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Measuring the Focal Spot Diameter of Laser Radiation by a Thin-Wire Bolometer

Telecommunications and Radio Engineering ◽

10.1615/telecomradeng.v53.i7-8.210 ◽

1999 ◽

Vol 53 (7-8) ◽

pp. 133-137 ◽

Cited By ~ 1

Author(s):

V. M. Kuzmichov ◽

S. V. Pogorelov

Keyword(s):

Laser Radiation ◽

Focal Spot ◽

Thin Wire ◽

Spot Diameter ◽

Focal Spot Diameter

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

EPJ Web of Conferences ◽

10.1051/epjconf/201818301028 ◽

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.

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Laser and target experiments on KrF GARPUN laser installation at FIAN

Laser and Particle Beams ◽

10.1017/s0263034699171064 ◽

1999 ◽

Vol 17 (1) ◽

pp. 69-88 ◽

Cited By ~ 8

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.

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High-precision small-scale laser focal spot measurements

Laser and Particle Beams ◽

10.1017/s0263034612001073 ◽

2013 ◽

Vol 31 (1) ◽

pp. 177-183 ◽

Cited By ~ 3

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.

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Role of the Features of Focused Laser Beam at Pulsed Laser Cutting

Acta Materialia Transilvanica ◽

10.33924/amt-2019-02-09 ◽

2019 ◽

Vol 2 (2) ◽

pp. 115-120

Author(s):

György Meszlényi ◽

Enikő Bitay

Keyword(s):

Laser Beam ◽

Focal Spot ◽

Beam Quality ◽

Original Data ◽

Rayleigh Length ◽

Two Factors ◽

Focal Spot Diameter ◽

New Equation ◽

The Given

Abstract In this article investigation of the roles of two important factors of focused laser beam, the focal spot diameter and the Rayleigh length as determining variables of the beam quality were made. The equations of these two factors are based on those most commonly used in the literature. The exchange between three different beam quality numbers were shown. It is proven on the basis of the scientific literature, that the beam quality degrades compared to the original data given by the factory of laser. The causes of the beam quality degradation are lens aberrations in the optical path of the given laser, and the shifting of the beam propagation ratio (M2) to higher values. A new equation for estimation of the new, lowest value for M2 factor is presented, based on the comparison of the laser cut material thickness to the depth of focus, which is two times the Rayleigh length.

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1178 J, 527 nm near diffraction limited laser based on a complete closed-loop adaptive optics controlled off-axis multi-pass amplification laser system

High Power Laser Science and Engineering ◽

10.1017/hpl.2021.3 ◽

2021 ◽

Vol 9 ◽

Author(s):

Deen Wang ◽

Xin Zhang ◽

Wanjun Dai ◽

Ying Yang ◽

Xuewei Deng ◽

...

Keyword(s):

Laser Beam ◽

Adaptive Optics ◽

Closed Loop ◽

Focal Spot ◽

Beam Quality ◽

Laser System ◽

Diffraction Limit ◽

Kdp Crystal ◽

Main Amplifier

Abstract A 1178 J near diffraction limited 527 nm laser is realized in a complete closed-loop adaptive optics (AO) controlled off-axis multi-pass amplification laser system. Generated from a fiber laser and amplified by the pre-amplifier and the main amplifier, a 1053 nm laser beam with the energy of 1900 J is obtained and converted into a 527 nm laser beam by a KDP crystal with 62% conversion efficiency, 1178 J and beam quality of 7.93 times the diffraction limit (DL). By using a complete closed-loop AO configuration, the static and dynamic wavefront distortions of the laser system are measured and compensated. After correction, the diameter of the circle enclosing 80% energy is improved remarkably from 7.93DL to 1.29DL. The focal spot is highly concentrated and the 1178 J, 527 nm near diffraction limited laser is achieved.

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