On The Influence Of Surface Condition On Air Plasma Formation Near Metals Irradiated By Microsecond TEA-CO2 Laser Pulses

1983 ◽  
Author(s):  
I. Ursu ◽  
Ileana Apostol ◽  
Doina Barbulescu ◽  
V. Lupei ◽  
I. N. Mihailescu ◽  
...  
Keyword(s):  
Surface Condition ◽  
Laser Pulses ◽  
Plasma Formation ◽  
Air Plasma

On the influence of surface condition on air plasma formation near metals irradiated by microsecond TEA CO2laser pulses

1984 ◽  
Vol 17 (4) ◽  
pp. 709-720 ◽  
Author(s):  
I Ursu ◽  
I Apostol ◽  
D Craciun ◽  
M Dinescu ◽  
I N Mihailescu ◽  
...  
Keyword(s):  
Surface Condition ◽  
Plasma Formation ◽  
Air Plasma

Transient reflectivity and transmission changes during plasma formation and ablation in fused silica induced by femtosecond laser pulses

2008 ◽  
Vol 92 (4) ◽  
pp. 803-808 ◽  
Author(s):  
D. Puerto ◽  
W. Gawelda ◽  
J. Siegel ◽  
J. Bonse ◽  
G. Bachelier ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Fused Silica ◽  
Plasma Formation

scholarly journals Absorption of ultrashort laser pulses in solid targets

1991 ◽  
Vol 9 (2) ◽  
pp. 465-475 ◽  
Author(s):  
F. Cornolti ◽  
P. Mulser ◽  
M. Hahn
Keyword(s):  
Laser Light ◽  
Plasma Heating ◽  
Normal Incidence ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Plasma Formation ◽  
Ultrashort Laser Pulses ◽  
Heating Process ◽  
Strong Electron ◽  
Collisional Ionization

Femtosecond laser pulses are capable of producing very high light intensities at moderate pulse energies. We study the laser light absorption at flux densities of 1017 W/cm2 and higher during the plasma formation and the plasma heating process. In the first stage multiphoton and collisional ionization dominate. Modification of the inverse bremsstrahlung absorption occur owing to ionization dephasing. In the second stage beam energy conversion is mainly by collisional absorption at normal incidence, and by resonance absorption at oblique illumination. Simultaneously strong electron heat conduction provides for plasma formation and heating in deeper layers of the solid not accessible to the laser light. The penetration depth of the laser beam is modified by the anomalous skin effect. The electron-ion collision frequency at the high laser intensities under consideration is determined by the oscillation energy of the electrons rather than by their thermal motion. Although it reaches high values (1014-1016 S-1), all kinds of solid targets become strongly reflecting (>60%) owing to the formation of electron densities largely exceeding those of solid-state plasmas. Effects modifying the degree of absorption are briefly discussed.

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