Improved two-temperature model including electron density of states effects for Au during femtosecond laser pulses

2012 ◽  
Vol 152 (2) ◽  
pp. 108-111 ◽  
Author(s):  
Ranran Fang ◽  
Hua Wei ◽  
Zhihua Li ◽  
Duanming Zhang
Keyword(s):  
Femtosecond Laser ◽  
Electron Density ◽  
Density Of States ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Temperature Model ◽  
Electron Density Of States ◽  
Two Temperature

Numerical Analysis on the Feasibility of Laser Microwelding of Metals by Femtosecond Laser Pulses Using ABAQUS

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Dongkyun Lee ◽  
Elijah Kannatey-Asibu
Keyword(s):  
Pulse Duration ◽  
Ultrafast Lasers ◽  
Short Pulse ◽  
Material Model ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Ultrafast Laser ◽  
Temperature Model ◽  
Laser Microwelding ◽  
Two Temperature

Ultrafast lasers of subpicosecond pulse duration have the potential for laser microwelding of micronscale fusion zone. Due to the extremely short pulse duration, laser-metal interaction involving ultrafast laser pulses should be analyzed using the two-temperature model. In this study, the two-temperature model is analyzed using ABAQUS to study the feasibility of laser microwelding with ultrafast laser. A material model is constructed using material properties and the subsurface boiling model. The model is validated using experimental results from the literature. Laser processing parameters of repetition rate, pulse duration, and focal radius are then investigated, in terms of molten pool generated in the material and requirements on those parameters for laser microwelding using ultrafast lasers are discussed.

scholarly journals Ultra-bright keV X-ray source generated by relativistic femtosecond laser pulse interaction with thin foils and its possible application for HEDS investigations

2017 ◽  
Vol 35 (3) ◽  
pp. 450-457 ◽  
Author(s):  
A.Y. Faenov ◽  
T.A. Pikuz ◽  
G.A. Vergunova ◽  
S.A. Pikuz ◽  
I.Y. Skobelev ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
One Dimensional ◽  
X Ray ◽  
Exotic States ◽  
Solid Density ◽  
Thin Foils ◽  
Two Temperature ◽  
Laser Pulse Interaction

AbstractIt was shown (Faenov et al., 2015b) that the energy of femtosecond laser pulses with relativistic intensity approaching to ~1021 W/cm2 is efficiently converted to X-ray radiation and produces exotic states in solid density plasma periphery. We propose and show by one-dimensional two-temperature hydrodynamic modeling, that applying two such unique ultra-bright X-ray sources with intensities above 1017 W/cm2 – allow to generate shock waves with strength of up to some hundreds Mbar, which could give new opportunities for studies of matter in extreme conditions.

Localized Electron Evolution Induced by Femtosecond Laser Pulses in Water

2001 ◽  
Author(s):  
C. H. Fan ◽  
J. Sun ◽  
J. P. Longtin
Keyword(s):  
Femtosecond Laser ◽  
Electron Density ◽  
Inhomogeneous Plasma ◽  
Optical Breakdown ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Rate Equations ◽  
Focal Region ◽  
Ultrashort Laser

Abstract Optical breakdown by ultrashort laser pulses in dielectrics presents an efficient method to deposit laser energy into materials that otherwise exhibit minimal absorption at low laser intensities. During optical breakdown, a high density of free electrons is formed in the material, which dominates energy absorption, and, in turn, the material removal rate during ultrafast laser-material processing. Classical models assume spatially uniform electron population and constant laser intensity in the focal region, which results in a time-dependent expressions only, i.e., the rate equations, to predict electron evolution induced by nanosecond and picosecond pulses. For femtosecond pulses, however, the small spatial extent of the pulse requires that the pulse propagation be considered, which results in inhomogeneous plasma and localized electron formation during optical breakdown. In this work, a femtosecond breakdown model is combined with the classical rate equations to determine both time- and position-dependent electron density during femtosecond optical breakdown in water. The model exhibits good agreement when compared with experimental results. For other transparent or moderately absorbing dielectric media, the model also shows promise for determining the time- and position-dependent electron evolution induced by ultrashort laser pulses. Another interesting result is that the maximum electron density formed during femtosecond-laser-induced optical breakdown can exceed the conventional limit imposed by the plasma frequency.

Inorganic-organic Hybrid Materials for Real 3-D Sub-νm Lithography

2003 ◽  
Vol 780 ◽  
Author(s):  
R. Houbertz ◽  
J. Schulz ◽  
L. Fröhlich ◽  
G. Domann ◽  
M. Popall ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Sol Gel ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Hybrid Polymer ◽  
Organic Hybrid ◽  
Two Photon ◽  
Applied Technology ◽  
Scale Structures ◽  
Sol Gel Synthesis

AbstractReal 3-D sub-νm lithography was performed with two-photon polymerization (2PP) using inorganic-organic hybrid polymer (ORMOCER®) resins. The hybrid polymers were synthesized by hydrolysis/polycondensation reactions (modified sol-gel synthesis) which allows one to tailor their material properties towards the respective applications, i.e., dielectrics, optics or passivation. Due to their photosensitive organic functionalities, ORMOCER®s can be patterned by conventional photo-lithography as well as by femtosecond laser pulses at 780 nm. This results in polymerized (solid) structures where the non-polymerized parts can be removed by conventional developers.ORMOCER® structures as small as 200 nm or even below were generated by 2PP of the resins using femtosecond laser pulses. It is demonstrated that ORMOCER®s have the potential to be used in components or devices built up by nm-scale structures such as, e.g., photonic crystals. Aspects of the materials in conjunction to the applied technology are discussed.

Ablation of metals with femtosecond laser pulses

2001 ◽  
Author(s):  
K. H. Leong ◽  
T. Y. Plew ◽  
R. L. Maynard ◽  
A. A. Said ◽  
L. A. Walker
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses
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