Concerning one mechanism of laser-radiation wave-absorption propagation in optical breakdown in disperse media

1984 ◽  
Vol 5 (2) ◽  
pp. 252-254
Author(s):  
A. P. Budnik ◽  
A. G. Popov
Keyword(s):  
Laser Radiation ◽  
Optical Breakdown ◽  
Wave Absorption ◽  
Radiation Wave

Optical breakdown of helium in Bessel laser radiation beams

1998 ◽  
Vol 28 (10) ◽  
pp. 910-916 ◽  
Author(s):  
N E Andreev ◽  
L Ya Margolin ◽  
I V Pleshanov ◽  
Lev N Pyatnitskii
Keyword(s):  
Laser Radiation ◽  
Optical Breakdown ◽  
Radiation Beams

The Analysis of Influence of Characteristics of Radiation of CO2 and Fiber Lasers on the Form and Depth of the Destroyed Surface of а Metal

2014 ◽  
Vol 9 (1) ◽  
pp. 62-69
Author(s):  
Aleksandr Zaitsev ◽  
Oleg Kovalev ◽  
Elena Smirnova
Keyword(s):  
Stainless Steel ◽  
Comparative Analysis ◽  
Laser Radiation ◽  
Laser Power ◽  
Laser Cutting ◽  
Fiber Lasers ◽  
Steel Sheet ◽  
Wave Length ◽  
Stainless Steel Sheet ◽  
Radiation Wave

On the basis of model ideas of interaction of laser radiation with metals the results of theoretical and research of influence of radiation wave length with circular polarization of a laser beam on a form of a destroyed surface of stainless steel sheet at a variation of laser power and material thickness are presented. The special attention is paid to the comparative analysis of efficiency of destruction of metal at CO2 laser (with λ = 10.6мкм), and fiber laser (with λ = 1.07мкм), which widely now in use in technological complexes on laser cutting of various sheet materials

scholarly journals Time-Resolved Spectroscopy Diagnostic of Laser-Induced Optical Breakdown

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Christian G. Parigger ◽  
James O. Hornkohl ◽  
László Nemes
Keyword(s):  
Laser Radiation ◽  
Nd:Yag Laser ◽  
Accurate Determination ◽  
Optical Breakdown ◽  
Emission Spectra ◽  
Equilibrium Temperature ◽  
Rotational Line ◽  
Molecular Spectra ◽  
Balmer Series ◽  
Time Resolved

Transient laser plasma is generated in laser-induced optical breakdown (LIOB). Here we report experiments conducted with 10.6-micron CO2 laser radiation, and with 1.064-micron fundamental, 0.532-micron frequency-doubled, 0.355-micron frequency-tripled Nd:YAG laser radiation. Characterization of laser induced plasma utilizes laser-induced breakdown spectroscopy (LIBS) techniques. Atomic hydrogen Balmer series emissions show electron number density of 1017 cm−3 measured approximately 10 μs and 1 μs after optical breakdown for CO2 and Nd:YAG laser radiation, respectively. Recorded molecular recombination emission spectra of CN and C2 Swan bands indicate an equilibrium temperature in excess of 7000 Kelvin, inferred for these diatomic molecules. Reported are also graphite ablation experiments where we use unfocused laser radiation that is favorable for observation of neutral C3 emission due to reduced C3 cation formation. Our analysis is based on computation of diatomic molecular spectra that includes accurate determination of rotational line strengths, or Hönl-London factors.

Optical breakdown of quartz glass by XeF laser radiation

1994 ◽  
Vol 24 (4) ◽  
pp. 307-310 ◽  
Author(s):  
A V Amosov ◽  
V S Barabanov ◽  
S Yu Gerasimov ◽  
Nikolai V Morozov ◽  
P B Sergeev ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Quartz Glass ◽  
Optical Breakdown

Spatial distribution of laser radiation scattered in a plasma formed by optical breakdown of a gas

1994 ◽  
Vol 24 (12) ◽  
pp. 1092-1096 ◽  
Author(s):  
Igor' A Bufetov ◽  
G A Bufetova ◽  
V B Fyodorov
Keyword(s):  
Spatial Distribution ◽  
Laser Radiation ◽  
Optical Breakdown

scholarly journals Case Report: Investigation of the Time Evolution of Optical Breakdown Plasma During Irradiation of Aqueous Solutions of Fe Nanoparticles

2021 ◽  
Vol 9 ◽  
Author(s):  
Ilya V. Baimler ◽  
Viktor K. Chevokin ◽  
Vitaliy A. Podvyaznikov ◽  
Sergey V. Gudkov
Keyword(s):  
Case Report ◽  
Water Vapor ◽  
Laser Radiation ◽  
Aqueous Solutions ◽  
Optical Breakdown ◽  
Maximum Size ◽  
Maximum Intensity ◽  
Initial Stage ◽  
Fe Nanoparticles ◽  
Breakdown Plasma

The time sweeps of images of optical breakdown plasma flashes under irradiation of aqueous solutions of Fe nanoparticles with Nd: YAG laser radiation (λ = 1,064 nm, τ = 10 ns, ν = 10 kHz, ε = 2 mJ) are studied. It is shown that the sizes of plasma flares, the plasma glow intensity, and the time to reach the maximum intensity are concentrated around certain values. So, for example, the values of 30 μm are most typical for the maximum size of flares. The maximum luminescence is usually reached in 3–4 ns. It is found that at initial stage of optical breakdown process the water-vapor boundary moves at typical speed of 11 km/s and have maximum and minimum values at 15 and 4 km/s respectively. It is assumed in this work that such a distribution may be associated with the initiation of breakdown on nanoparticles located in different places of the laser radiation waist.

scholarly journals Sequences of Sub-Microsecond Laser Pulses for Material Processing: Modeling of Coupled Gas Dynamics and Heat Transfer

2019 ◽  
Vol 9 (22) ◽  
pp. 4785
Author(s):  
Gusarov ◽  
Kovalev
Keyword(s):  
Heat Transfer ◽  
Laser Radiation ◽  
Laser Processing ◽  
Gas Dynamics ◽  
Optical Breakdown ◽  
Single Pulse ◽  
Laser Pulses ◽  
High Repetition Rate ◽  
Heat Accumulation ◽  
Pulse Separation

Multipulse laser processing of materials is promising because of the additional possibilities to control the thickness of the treated and the heat-affected zones and the energy efficiency. To study the physics of mutual interaction of pulses at high repetition rate, a model is proposed where heat transfer in the target and gas-dynamics of vapor and ambient gas are coupled by the gas-dynamic boundary conditions of evaporation/condensation. Numerical calculations are accomplished for a substrate of an austenitic steel subjected to a 300 ns single pulse of CO2 laser and a sequence of the similar pulses with lower intensity and 10 μs inter-pulse separation assuring approximately the same thermal impact on the target. It is revealed that the pulses of the sequence interact due to heat accumulation in the target but they cannot interact through the gas phase. Evaporation is considerably more intensive at the single-pulse processing. The vapor is slightly ionized and absorbs the infrared laser radiation by inverse bremsstrahlung. The estimated absorption coefficient and the optical thickness of the vapor domain are considerably greater for the single-pulse regime. The absorption initiates optical breakdown and the ignition of plasma shielding the target from laser radiation. The multipulse laser processing can be applied to avoid plasma ignition.

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