Multiphoton absorption of ultrashort laser pulses in optical materials of multilayer coatings at near-damage-threshold fluence

2020 ◽  
Author(s):  
Vitaly E. Gruzdev ◽  
Kyle Kafka
Keyword(s):  
Optical Materials ◽  
Damage Threshold ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Multiphoton Absorption ◽  
Multilayer Coatings ◽  
Threshold Fluence ◽  
Ultrashort Laser

scholarly journals Ablation of BaWO4 Crystal by Ultrashort Laser Pulses

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 754
Author(s):  
Igor Kinyaevskiy ◽  
Pavel Danilov ◽  
Nikita Smirnov ◽  
Sergey Kudryashov ◽  
Andrey Koribut ◽  
...  
Keyword(s):  
Crystal Surface ◽  
Damage Threshold ◽  
Single Pulse ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Pulse Irradiation ◽  
Optical Damage ◽  
Order Of Magnitude ◽  
Ultrashort Laser ◽  
Optical Damage Threshold

Ablation of BaWO4 Raman crystals with different impurity concentrations by ultrashort laser pulses was experimentally studied. Laser pulses with duration varying from 0.3 ps to 1.6 ps at wavelengths of 515 nm and 1030 nm were applied. A single-pulse optical damage threshold of the crystal surface changed from 1.3 J/cm2 to 4.2 J/cm2 depending on the laser pulse parameters and BaWO4 crystal purity. The optical damage threshold under multi-pulse irradiation was an order of magnitude less.

scholarly journals Ultrafast laser heating of non-plasmonic nanocylinders

2021 ◽  
Vol 2015 (1) ◽  
pp. 012104
Author(s):  
Olesia Pashina ◽  
Daniil Ryabov ◽  
George Zograf ◽  
Sergey Makarov ◽  
Mihail Petrov
Keyword(s):  
Damage Threshold ◽  
Laser Pulses ◽  
Dielectric Substrate ◽  
Ultrashort Laser Pulses ◽  
Experimental Conditions ◽  
Pulsed Heating ◽  
Heating Effects ◽  
Ultrashort Laser ◽  
Two Temperature ◽  
Thermal Stability Of

Abstract We develop a model describing non-equilibrium processes under the excitation of resonant semiconductor nanostructures with ultrashort laser pulses with a duration of about 100 fs. We focus on the heating effects related to pulsed excitation with account on free carriers generation, thermalization, and relaxation. The heat exchange between the electron and phonon system is treated within the two-temperature model. We applied the developed model to describing pulsed heating of silicon nanocylinder on top of a dielectric substrate. We come up with estimations of the thermal damage threshold of the considered structures which provides the limits for the experimental conditions and ensures thermal stability of the samples.

scholarly journals Femtosecond Laser Assisted Crystallization of Gold Thin Films

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1186
Author(s):  
Ayesha Sharif ◽  
Nazar Farid ◽  
Rajani K. Vijayaraghavan ◽  
Patrick J. McNally ◽  
Gerard M. O’Connor
Keyword(s):  
Thin Films ◽  
Femtosecond Laser ◽  
Quartz Substrate ◽  
Damage Threshold ◽  
Laser Pulses ◽  
Industrial Applications ◽  
Ultrashort Laser Pulses ◽  
Gold Films ◽  
Gold Thin Films ◽  
Ultrashort Laser

We propose a novel low temperature annealing method for selective crystallization of gold thin films. Our method is based on a non-melt process using highly overlapped ultrashort laser pulses at a fluence below the damage threshold. Three different wavelengths of a femtosecond laser with the fundamental (1030 nm), second (515 nm) and third (343 nm) harmonic are used to crystallize 18-nm and 39-nm thick room temperature deposited gold thin films on a quartz substrate. Comparison of laser wavelengths confirms that improvements in electrical conductivity up to 40% are achievable for 18-nm gold film when treated with the 515-nm laser, and the 343-nm laser was found to be more effective in crystallizing 39-nm gold films with 29% improvement in the crystallinity. A two-temperature model provides an insight into ultrashort laser interactions with gold thin films and predicts that applied fluence was insufficient to cause melting of gold films. The simulation results suggest that non-equilibrium energy transfer between electrons and lattice leads to a solid-state and melt-free crystallization process. The proposed low fluence femtosecond laser processing method offers a possible solution for a melt-free thin film crystallization for wide industrial applications.

Model of the final borehole geometry for helical laser drilling

2018 ◽  
Vol 7 (3) ◽  
pp. 183-188
Author(s):  
Alexander Kroschel ◽  
Andreas Michalowski ◽  
Thomas Graf
Keyword(s):  
Experimental Data ◽  
Stainless Steel ◽  
Cross Sections ◽  
Ablation Threshold ◽  
Laser Pulses ◽  
Laser Drilling ◽  
Ultrashort Laser Pulses ◽  
Threshold Fluence ◽  
Different Shapes ◽  
Ultrashort Laser

Abstract A model for predicting the borehole geometry for laser drilling is presented based on the calculation of a surface of constant absorbed fluence. It is applicable to helical drilling of through-holes with ultrashort laser pulses. The threshold fluence describing the borehole surface is fitted for best agreement with experimental data in the form of cross-sections of through-holes of different shapes and sizes in stainless steel samples. The fitted value is similar to ablation threshold fluence values reported for laser ablation models.

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.

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