scholarly journals Eyesafe coherent detection wind lidar based on a beam-combined pulsed laser source

2015 ◽  
Vol 40 (6) ◽  
pp. 1030 ◽  
Author(s):  
L. Lombard ◽  
M. Valla ◽  
C. Planchat ◽  
D. Goular ◽  
B. Augère ◽  
...  
Keyword(s):  
Pulsed Laser ◽  
Coherent Detection ◽  
Laser Source ◽  
Wind Lidar

scholarly journals Smoothing additive manufactured parts using ns-pulsed laser radiation

2021 ◽  
Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni
Keyword(s):  
Surface Roughness ◽  
Mechanical Performance ◽  
State Of The Art ◽  
Pulsed Laser ◽  
Industrial Applications ◽  
Laser Source ◽  
Pulsed Laser Radiation ◽  
Current State ◽  
The Impact

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.

Hologram indexing in LiNbO_3 with a tunable pulsed laser source

1979 ◽  
Vol 18 (15) ◽  
pp. 2555 ◽  
Author(s):  
D. A. Woodbury ◽  
T. A. Rabson ◽  
F. K. Tittel
Keyword(s):  
Pulsed Laser ◽  
Laser Source

Pulsed Laser Deposition (PLD) Technique to Prepare Biocompatible Thin Films

2006 ◽  
Vol 49 ◽  
pp. 56-61 ◽  
Author(s):  
Joseph J. Beltrano ◽  
Lorenzo Torrisi ◽  
Anna Maria Visco ◽  
Nino Campo ◽  
E. Rapisarda
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Target Material ◽  
Xrd Analysis ◽  
Spot Size ◽  
Laser Deposition ◽  
Laser Source ◽  
Medical Field ◽  
Hot Plasma ◽  
532 Nm

A Nd:YAG laser is employed to ablate different materials useful in the bio-medical field. The laser source operates in the IR (1064 nm), VIS (532 nm) and UV (355 nm) regions with a pulse duration of 3-9 ns, a pulse energy of 3-300 mJ, a spot size of 1 mm2 and a repetition rate of 1- 30 Hz. Target material of interest are Titanium, Carbon, Hydroxyapatite (HA) and Polyethylene (PE). Laser irradiation occurs in vacuum, where hot plasma is generated, and thin films are deposited on near substrates. Generally, substrates of silicon, titanium, titanium-alloys and polymers were employed. Biocompatible thin films are investigated with different surface techniques, such as IR spectroscopy, Raman spectroscopy, XRD analysis and SEM investigations. Depending of the kind of possible application, films require special properties concerning the grain size, porosity, uniformity, wetting, hardness, adhesion, crystallinity and composition. The obtained results will be presented and discussed with particular regard to HA..

The Doppler Aerosol Wind (DAWN) Airborne, Wind-Profiling Coherent-Detection Lidar System: Overview and Preliminary Flight Results

2014 ◽  
Vol 31 (4) ◽  
pp. 826-842 ◽  
Author(s):  
Michael J. Kavaya ◽  
Jeffrey Y. Beyon ◽  
Grady J. Koch ◽  
Mulugeta Petros ◽  
Paul J. Petzar ◽  
...  
Keyword(s):  
Laser Pulse ◽  
High Energy ◽  
Coherent Detection ◽  
Lidar System ◽  
Airborne Measurements ◽  
Secondary Mirror ◽  
Wind Measurements ◽  
Wind Lidar ◽  
Aerosol Backscatter ◽  
Flight Measurements

Abstract The first airborne wind measurements of a pulsed, 2-μm solid-state, high-energy, wind-profiling lidar system for airborne measurements are presented. The laser pulse energy is the highest to date in an eye-safe airborne wind lidar system. This energy, the 10-Hz laser pulse rate, the 15-cm receiver diameter, and dual-balanced coherent detection together have the potential to provide much-improved lidar sensitivity to low aerosol backscatter levels compared to earlier airborne-pulsed coherent lidar wind systems. Problems with a laser-burned telescope secondary mirror prevented a full demonstration of the lidar’s capability, but the hardware, algorithms, and software were nevertheless all validated. A lidar description, relevant theory, and preliminary results of flight measurements are presented.

UV-Induced Fractal Surfaces

Fractals ◽  
1997 ◽  
Vol 05 (02) ◽  
pp. 275-280 ◽  
Author(s):  
Cs. Beleznai ◽  
R. Vajtai ◽  
L. Nánai
Keyword(s):  
Surface Morphology ◽  
Structural Parameters ◽  
Strong Dependence ◽  
Pulsed Laser ◽  
Fractal Dimensions ◽  
Laser Source ◽  
Physical Parameters ◽  
Fractal Surfaces

Poly (tetrafluorethylene) and polyimide samples were irradiated by a pulsed laser source at 308 nm and the resulting surface morphology was investigated. The photoablated surfaces show a strong dependence on the optical and structural parameters of the polymers. The roughness of the fractal surfaces has been characterized by means of calculating their fractal dimensions and the results are interpreted as a function of the polymer physical parameters.

Fiber-coupled three-micron pulsed laser source for CFRP laser treatment

2018 ◽  
Author(s):  
Sebastian Nyga ◽  
David Blass ◽  
Veronika Katzy ◽  
Thomas Westphalen ◽  
Bernd Jungbluth ◽  
...  
Keyword(s):  
Laser Treatment ◽  
Pulsed Laser ◽  
Laser Source

All-fiber pulsed laser source based on Raman dissipative soliton generation for biological tissue analysis

2020 ◽  
Author(s):  
Innokentiy Zhdanov ◽  
Denis S. Kharenko ◽  
Anastasia E. Bednyakova ◽  
Mikhail P. Fedoruk ◽  
Sergey A. Babin
Keyword(s):  
Biological Tissue ◽  
Pulsed Laser ◽  
Dissipative Soliton ◽  
Laser Source ◽  
Tissue Analysis ◽  
Soliton Generation

A sub-nanosecond narrow-linewidth pulsed laser source with controllable repetition rate

Laser Physics ◽  
2013 ◽  
Vol 23 (7) ◽  
pp. 075101
Author(s):  
L Q Niu ◽  
C X Gao ◽  
H D He ◽  
L Feng ◽  
Z Y Cao ◽  
...  
Keyword(s):  
Repetition Rate ◽  
Pulsed Laser ◽  
Laser Source ◽  
Narrow Linewidth

scholarly journals Transient Model for CW and Pulsed Laser Machining of Ablating/Decomposing Materials—Approximate Analysis

1996 ◽  
Vol 118 (3) ◽  
pp. 774-780 ◽  
Author(s):  
M. F. Modest
Keyword(s):  
Three Dimensional ◽  
Pulsed Laser ◽  
Computer Time ◽  
Single Step ◽  
Laser Source ◽  
Laser Machining ◽  
Transient Model ◽  
One Dimensional ◽  
Cpu Time ◽  
Order Of Magnitude

Approximate, quasi-one-dimensional conduction models have been developed to predict the changing shape of holes, single grooves, or overlapping grooves carved by ablation into a thick solid that is irradiated by a moving laser source. For CW or pulsed laser operation a simple integral method is presented, which predicts shapes and removal rates with an accuracy of a few percent, while requiring one order of magnitude less CPU time than a three-dimensional, numerical solution. For pulsed operation a “full-pulse” model is presented, computing the erosion from an entire pulse in a single step, and reducing computer time by another order of magnitude.

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