scholarly journals Investigation of propagation dynamics of material deformations caused by laser pulse action

2021 ◽  
Vol 2144 (1) ◽  
pp. 012008
Author(s):  
A F Banishev
Keyword(s):  
Spatial Distribution ◽  
Laser Pulse ◽  
Laser Pulses ◽  
Pulse Action ◽  
Mechanical Stresses ◽  
Powerful Laser ◽  
Phosphor Powder ◽  
Glow Intensity ◽  
Evolution Dynamics ◽  
Laser Pulse Action

Abstract The mechanoluminescent materials attract increasing attention of scientists due to their capability of visualizing the mechanical stresses and deformations experienced by them. The deformations of materials arising under the action of powerful laser pulses were studied. The composite mechanoluminescent materials based on the polymer and phosphor powder were used for visualization and registration of deformation evolution dynamics. The mechanoluminescent materials were deposited on the surface of the materials under study. It has been shown that the spatial distribution of glow intensity of the mechanoluminescent layer and the rate of its change make possible judging the value and rate of material deformation under laser pulses.

scholarly journals Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

2015 ◽  
Vol 6 ◽  
pp. 893-900 ◽  
Author(s):  
Valentin Serban Teodorescu ◽  
Cornel Ghica ◽  
Adrian Valentin Maraloiu ◽  
Mihai Vlaicu ◽  
Andrei Kuncser ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Pulse ◽  
Laser Irradiation ◽  
Film Surface ◽  
Laser Pulses ◽  
Pulse Action ◽  
Pulse Field ◽  
Fast Diffusion ◽  
Absorption Length ◽  
Modified Layer

Laser pulse processing of surfaces and thin films is a useful tool for amorphous thin films crystallization, surface nanostructuring, phase transformation and modification of physical properties of thin films. Here we show the effects of nanostructuring produced at the surface and under the surface of amorphous GeTiO films through laser pulses using fluences of 10–30 mJ/cm2. The GeTiO films were obtained by RF magnetron sputtering with 50:50 initial atomic ratio of Ge:TiO2. Laser irradiation was performed by using the fourth harmonic (266 nm) of a Nd:YAG laser. The laser-induced nanostructuring results in two effects, the first one is the appearance of a wave-like topography at the film surface, with a periodicity of 200 nm and the second one is the structure modification of a layer under the film surface, at a depth that is related to the absorption length of the laser radiation. The periodicity of the wave-like relief is smaller than the laser wavelength. In the modified layer, the Ge atoms are segregated in spherical amorphous nanoparticles as a result of the fast diffusion of Ge atoms in the amorphous GeTiO matrix. The temperature estimation of the film surface during the laser pulses shows a maximum of about 500 °C, which is much lower than the melting temperature of the GeTiO matrix. GeO gas is formed at laser fluences higher than 20 mJ/cm2 and produces nanovoids in the laser-modified layer at the film surface. A glass transition at low temperatures could happen in the amorphous GeTiO film, which explains the formation of the wave-like topography. The very high Ge diffusivity during the laser pulse action, which is characteristic for liquids, cannot be reached in a viscous matrix. Our experiments show that the diffusivity of atomic and molecular species such as Ge and GeO is very much enhanced in the presence of the laser pulse field. Consequently, the fast diffusion drives the formation of amorphous Ge nanoparticles through the segregation of Ge atoms in the GeTiO matrix. The nanostructuring effects induced by the laser irradiation can be used in functionalizing the surface of the films.

INCREASING OF THE SHARPNESS OF p–n JUNCTIONS BY LASER PULSES

NANO ◽  
2011 ◽  
Vol 06 (01) ◽  
pp. 31-40 ◽  
Author(s):  
E. L. PANKRATOV
Keyword(s):  
Spatial Distribution ◽  
Laser Pulse ◽  
Annealing Time ◽  
Multilayer Structure ◽  
Surface Region ◽  
Laser Pulses ◽  
Dopant Distribution ◽  
Dopant Redistribution ◽  
Junction Rectifiers

Dopant redistribution in a multilayer structure during annealing by laser pulses for production of implanted-junction rectifiers has been analyzed. The analysis shows that heating the surface region of the multilayer structure leads to increasing of previously described effect of simultaneously increasing of sharpness of implanted-junction rectifier and homogeneity of dopant distribution in doped area. It was found that the theoretical spatial distribution of dopant agrees with the experimental one. Annealing time has been optimized for laser pulse annealing.

The effect of pore formation on the reflectance of aluminum alloy 1421 during laser pulse action

2014 ◽  
Vol 40 (5) ◽  
pp. 435-437
Author(s):  
P. Yu. Kikin ◽  
V. N. Perevezentsev ◽  
E. E. Rusin
Keyword(s):  
Aluminum Alloy ◽  
Laser Pulse ◽  
Pore Formation ◽  
Pulse Action ◽  
Laser Pulse Action
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