Study of Hot Electron Transportation in Foils and Wedge Targets Irradiated with Ultrashort Laser Pulses

2007 ◽  
Author(s):  
B. Cho ◽  
J. Osterholz ◽  
G. Dyer ◽  
S. Kneip ◽  
D. Symes ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Hot Electron ◽  
Electron Transportation ◽  
Ultrashort Laser

Transient Reflectance Response to Hot Electron Relaxation in InP Based Films

2002 ◽  
Author(s):  
J. Michael Klopf ◽  
John L. Hostetler ◽  
Pamela M. Norris
Keyword(s):  
Thin Film ◽  
Transient Absorption ◽  
Film Growth ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Photon Absorption ◽  
Hot Electron ◽  
Carrier Relaxation ◽  
Hot Carrier ◽  
Ultrashort Laser

Advancements in technologies related to thin film growth have led to astoundingly complex integrated photonic devices. The reliability of these devices relies upon the precise control of the band gap and absorption mechanisms in the thin film structures. Photon absorption in these devices can result in a reduction of laser efficiency as well as thermal runaway. To improve device performance prediction, an increased understanding of the localized absorption processes is paramount. A pump-probe technique is being developed to measure the transient absorption during hot carrier relaxation. This method relies upon the generation of hot carriers by the absorption of an intense ultrashort laser pulse. The change in reflectance due to hot carrier generation and relaxation is monitored using a probe pulse focused at the center of the excited region. The transient reflectance is measured as a function of the relative delay between the pump and probe pulses. Utilizing ultrashort laser pulses (τp ∼ 190 fs) it is possible to attain sub-picosecond resolution of the transient reflectance during hot carrier relaxation. Transient changes in the reflectance can then be related to transient changes in the absorption mechanisms of the film. Preliminary measurements made with this technique have shown clear differences in the transient reflectance of doped and undoped Indium Phosphide (InP) based films. This study will form the basis for development of a transient thermoreflectance model during hot carrier relaxation in III-V semiconductors.

Welding characteristics of foturan glass using ultrashort laser pulses

2012 ◽  
Author(s):  
Isamu Miyamoto ◽  
Kristian Cvecek ◽  
Yasuhiro Okamoto ◽  
Michael Schmidt ◽  
Henry Helvajian
Keyword(s):  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Ultrashort Laser

Evaluation of Chip-Breakers Manufactured by Ultrashort Laser Pulses in Cemented Carbide Tools

2017 ◽  
Author(s):  
Marcelo Bertolete Carneiro ◽  
Patrícia Alves Barbosa ◽  
Ricardo Samad ◽  
NIlson Vieira ◽  
Wagner de Rossi ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Cemented Carbide ◽  
Cemented Carbide Tools ◽  
Ultrashort Laser

Picosecond Single-Photon and Femtosecond Two-Photon Pulsed Laser Stimulation for IC Characterization and Failure Analysis

2009 ◽  
Author(s):  
V. Pouget ◽  
E. Faraud ◽  
K. Shao ◽  
S. Jonathas ◽  
D. Horain ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Single Photon ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Laser Stimulation ◽  
Two Photon ◽  
Resolution Improvement ◽  
Ultrashort Laser

Abstract This paper presents the use of pulsed laser stimulation with picosecond and femtosecond laser pulses. We first discuss the resolution improvement that can be expected when using ultrashort laser pulses. Two case studies are then presented to illustrate the possibilities of the pulsed laser photoelectric stimulation in picosecond single-photon and femtosecond two-photon modes.

scholarly journals Super-Heavy Ions Acceleration Driven by Ultrashort Laser Pulses at Ultrahigh Intensity

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Pengjie Wang ◽  
Zheng Gong ◽  
Seong Geun Lee ◽  
Yinren Shou ◽  
Yixing Geng ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Ultrashort Laser

scholarly journals Analytical model for the depth progress of percussion drilling with ultrashort laser pulses

2021 ◽  
Vol 127 (5) ◽  
Author(s):  
Daniel Holder ◽  
Rudolf Weber ◽  
Thomas Graf ◽  
Volkher Onuseit ◽  
David Brinkmeier ◽  
...  
Keyword(s):  
Analytical Model ◽  
Experimental Validation ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Picosecond Pulses ◽  
Hole Depth ◽  
Laser Percussion Drilling ◽  
Pulse Energies ◽  
Ultrashort Laser ◽  
Percussion Drilling

AbstractA simplified analytical model is presented that predicts the depth progress during and the final hole depth obtained by laser percussion drilling in metals with ultrashort laser pulses. The model is based on the assumption that drilled microholes exhibit a conical shape and that the absorbed fluence linearly increases with the depth of the hole. The depth progress is calculated recursively based on the depth changes induced by the successive pulses. The experimental validation confirms the model and its assumptions for percussion drilling in stainless steel with picosecond pulses and different pulse energies.

scholarly journals High-quality percussion drilling with ultrashort laser pulses

2021 ◽  
Vol 127 (9) ◽  
Author(s):  
A. Feuer ◽  
R. Weber ◽  
R. Feuer ◽  
D. Brinkmeier ◽  
T. Graf
Keyword(s):  
Stainless Steel ◽  
Laser Fluence ◽  
Ablation Threshold ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
High Quality ◽  
Edge Quality ◽  
Ultrashort Laser ◽  
Percussion Drilling

AbstractThe influence of the laser fluence on the quality of percussion-drilled holes was investigated both experimentally and by an analytical model. The study reveals that the edge quality of the drilled microholes depends on the laser fluence reaching the rear exit of the hole and changes with the number of pulses applied after breakthrough. The minimum fluence that must reach the hole’s exit in order to obtain high-quality microholes in stainless steel was experimentally found to be 2.8 times the ablation threshold.

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