scholarly journals Variation of the band structure in DKDP crystal excited by intense sub-picosecond laser pulses

2018 ◽  
Vol 6 ◽  
Author(s):  
Xiaocong Peng ◽  
Yuanan Zhao ◽  
Yueliang Wang ◽  
Zhen Cao ◽  
Guohang Hu ◽  
...  
Keyword(s):  
Picosecond Laser ◽  
Laser Pulses ◽  
Multiphoton Absorption ◽  
Defect States ◽  
Absorption Mechanism ◽  
Excitation Laser ◽  
Mechanism Transition ◽  
Defect Species ◽  
Critical Intensity ◽  
Good Agreement

The nonlinear absorption (NLA) properties of potassium dideuterium phosphate crystals at 515 nm under different excitation laser intensities are investigated with the Z-scan technique. Two critical intensities are highlighted: the critical intensity for exciting the NLA and the critical intensity of the multiphoton absorption mechanism transition. Experimental results indicate the existence of defect states located in the band gap, which can be manipulated by varying laser intensity. A model based on the change of multiphoton absorption mechanism induced by the transformation of defect species is proposed to interpret the experiments. Modeling results are in good agreement with the experiment data.

Electric field probing by picosecond laser pulses

1992 ◽  
Vol 28 (12) ◽  
pp. 1137 ◽  
Author(s):  
A. Krotkus ◽  
V. Pašiškevičius
Keyword(s):  
Electric Field ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Picosecond Laser Pulses

scholarly journals Sputtering of Neutral Molecules and Molecular Ions From the Adenine Crystal Surface Induced by the UV Picosecond Laser Pulse

1982 ◽  
Vol 1 (1) ◽  
pp. 37-43 ◽  
Author(s):  
V. S. Antonov ◽  
V. S. Letokhov ◽  
Yu. A. Matveyets ◽  
A. N. Shibanov
Keyword(s):  
Laser Radiation ◽  
Kinetic Energy ◽  
Crystal Surface ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Molecular Ions ◽  
Laser Radiation Intensity ◽  
Ion Sputtering ◽  
Absorbed Energy ◽  
Picosecond Laser Pulse

This paper presents the results of observation of sputtering of neutral molecules and ions from the crystal adenine surface induced by fourth-harmonic Nd:YAG laser radiation with a pulse duration of 30 ps. The energy fluence of laser pulses was in the region (1–3) × 10−4 J/cm2. The kinetic energy distribution of the sputtered molecules spreads up to 0.7 eV. The experiment shows that the threshold of adenine molecular ion sputtering is connected with absorbed energy density in upper layers of the crystal surface but not by laser radiation intensity.

scholarly journals Surface treatment on cobalt and titanium alloys using picosecond laser pulses in burst mode

2020 ◽  
Vol 127 (1) ◽  
Author(s):  
Daniel Metzner ◽  
Peter Lickschat ◽  
Steffen Weißmantel
Keyword(s):  
Surface Treatment ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Laser Source ◽  
Time Interval ◽  
Cobalt Chromium ◽  
Burst Mode ◽  
Self Organized ◽  
Implant Alloys ◽  
Cobalt Chromium Molybdenum

AbstractThe authors report on the results of surface treatment experiments using a solid-state amplified laser source emitting laser pulses with a pulse duration of 10 ps. The laser source allows the generation of pulse trains (bursts) with an intra-burst pulse repetition rate of 80 MHz (pulse-to-pulse time interval about 12.5 ns) with up to eight pulses per burst. In this study a wavelength of 1064 nm was used to investigate both ablation of material and laser-induced surface modifications occuring in metallic implant alloys CoCrMo (cobalt-chromium-molybdenum) and TiAlV (titanium-aluminum-vanadium) in dependence of the number of pulses and fluences per pulse in the burst. By using the burst mode, a smoothing effect occurs in a certain parameter range, resulting in very low surface roughness of the generated microstructures. It is demonstrated that at fluences per pulse which are smaller than the material-specific ablation threshold, a self-organized pore formation takes place if a defined number of pulses per burst is used. Thus, the advantage of the MHz burst mode in terms of a possible surface modification is established.

Analogic Transmission Of Picosecond Laser Pulses Through Optical Step Index Optical Fiber

1985 ◽  
Author(s):  
C. Cavailler ◽  
D. Gontier ◽  
J. Launspach ◽  
C. Froehly ◽  
D. Largeau ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Step Index ◽  
Picosecond Laser Pulses

Two-photon photoemission from metals induced by picosecond laser pulses

1977 ◽  
Vol 15 (10) ◽  
pp. 4557-4563 ◽  
Author(s):  
J. H. Bechtel ◽  
W. Lee Smith ◽  
N. Bloembergen
Keyword(s):  
Picosecond Laser ◽  
Laser Pulses ◽  
Two Photon ◽  
Picosecond Laser Pulses

Shaping of picosecond laser pulses with THz intensitymodulation in the infrared, visible, and ultravioletranges

2021 ◽  
Author(s):  
Igor Kuzmin ◽  
Sergey Mironov ◽  
Mikhail Martyanov ◽  
Anatoly Poteomkin ◽  
Efim Khazanov
Keyword(s):  
Picosecond Laser ◽  
Laser Pulses ◽  
Picosecond Laser Pulses

Emission of molecular nitrogen at tight focusing of femtosecond laser pulses in air

2021 ◽  
pp. 42-48
Author(s):  
A.A. Ilyin ◽  
◽  
K.A. Shmirko ◽  
S.S. Golik ◽  
D.Yu. Proschenko ◽  
...  
Keyword(s):  
Particle Density ◽  
Molecular Nitrogen ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Plasma Particle ◽  
Sharp Drop ◽  
Radiation Level ◽  
Femtosecond Radiation ◽  
Tight Focusing ◽  
Good Agreement

A numerical model describing the dynamics of plasma particle density upon filamentation of femtosecond radiation in the air is presented. The simulation results are in good agreement with the experimental data. The pumping processes of the N2 and N2+ radiative levels are investigated. The model predicts a sharp drop in electron temperature and density within 1 ns. For the first positive nitrogen system, an excess of the population of the upper radiation level over the population of the lower one is observed for 550 ps.

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