Burst train generator of high energy femtosecond laser pulses for driving heat accumulation effect during micromachining

2015 ◽  
Vol 40 (9) ◽  
pp. 2064 ◽  
Author(s):  
Saeid Rezaei ◽  
Jianzhao Li ◽  
Peter R. Herman
2012 ◽  
Vol 285 (10-11) ◽  
pp. 2715-2718 ◽  
Author(s):  
Chi Zhang ◽  
Yu-ying Zhang ◽  
Ming-lie Hu ◽  
Si-jia Wang ◽  
You-jian Song ◽  
...  

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 347
Author(s):  
Dabu

This paper describes techniques for high-energy laser pulse amplification in multi-PW femtosecond laser pulses. Femtosecond laser pulses can be generated and amplified in laser media with a broad emission spectral bandwidth, like Ti:sapphire crystals. By chirped pulse amplification (CPA) techniques, hundred-Joule amplified laser pulses can be obtained. Multi-PW peak-power femtosecond pulses are generated after recompression of amplified chirped laser pulses. The characteristics and problems of large bandwidth laser pulses amplification in Ti:sapphire crystals are discussed. An alternative technique, based on optical parametric chirped pulse amplification (OPCPA) in nonlinear crystals, is presented. Phase-matching conditions for broad bandwidth parametric amplification in nonlinear crystals are inferred. Ultra-broad phase matching bandwidth of more than 100 nm, able to support the amplification of sub-10 fs laser pulses, are demonstrated in nonlinear crystals, such as Beta Barium Borate (BBO), Potassium Dideuterium Phosphate (DKDP), and Lithium Triborate (LBO). The advantages and drawbacks of CPA amplification in laser crystals and OPCPA in nonlinear crystals are discussed. A hybrid amplification method, which combines low-medium energy OPCPA in nonlinear crystals with high energy CPA in large aperture laser crystals, is described. This technique is currently used for the development of 10-PW laser systems, with sub-20 fs pulse duration and more than 1012 intensity contrast of output femtosecond pulses.


2021 ◽  
Vol 127 (7) ◽  
Author(s):  
A. Andreev ◽  
J. Imgrunt ◽  
V. Braun ◽  
I. Dittmar ◽  
U. Teubner

AbstractThe interaction of intense femtosecond laser pulses with solid targets is a topic that has attracted a large amount of interest in science and applications. For many of the related experiments a large energy deposition or absorption as well as an efficient coupling to extreme ultraviolet (XUV), X-ray photon generation, and/or high energy particles is important. Here, much progress has been made in laser development and in experimental schemes, etc. However, regarding the improvement of the target itself, namely its geometry and surface, only limited improvements have been reported. The present paper investigates the formation of laser-induced periodic surface structures (LIPSS or ripples) on polished thick copper targets by femtosecond Ti:sapphire laser pulses. In particular, the dependence of the ripple period and ripple height has been investigated for different fluences and as a function of the number of laser shots on the same surface position. The experimental results and the formation of ripple mechanisms on metal surfaces in vacuum by femtosecond laser pulses have been analysed and the parameters of the experimentally observed “gratings” interpreted on base of theoretical models. The results have been specifically related to improve high-intensity femtosecond-laser matter interaction experiments with the goal of an enhanced particle emission (photons and high energy electrons and protons, respectively). In those experiments the presently investigated nanostructures could be generated easily in situ by multiple pre-pulses irradiated prior to a subsequent much more intense main laser pulse.


2008 ◽  
Vol 93 (23) ◽  
pp. 231112 ◽  
Author(s):  
Masaaki Sakakura ◽  
Masahiro Shimizu ◽  
Yasuhiko Shimotsuma ◽  
Kiyotaka Miura ◽  
Kazuyuki Hirao

2000 ◽  
Vol 17 (2) ◽  
pp. 99-100 ◽  
Author(s):  
Zhong Li ◽  
An-Le Lei ◽  
Guo-Quan Ni ◽  
Zhi-Zhan Xu

2013 ◽  
Vol 21 (13) ◽  
pp. 15452 ◽  
Author(s):  
Sören Richter ◽  
Sven Döring ◽  
Frank Burmeister ◽  
Felix Zimmermann ◽  
Andreas Tünnermann ◽  
...  

1995 ◽  
Vol 397 ◽  
Author(s):  
F. Qian ◽  
R. K. Singh ◽  
S. Dutta ◽  
P.P. Pronko ◽  
W.H. Weber

ABSTRACTWe have deposited unhydrogenated diamond-like carbon (DLC) films with 100 femtosecond laser pulses, at intensities in the 3x1014 - 6.5x1015 W/cm2 range. Film surface topography, optical property, and bonding structure were examined, respectively, with atomic force microscopy (AFM), spectroscopie ellipsometry (SE) and Raman spectrometry. The femtosecond pulse generated plasma was studied through time-of-flight (TOF) experiment. The most probable kinetic energy of carbon ions was estimated to be in the 300 – 2000 eV range, increasing with laser intensity. In addition, a unique ‘suprathermal’ component with kinetic energy ranging from 4 to 40 keV was observed in the TOF spectrum. This high energy peak is believed to originate from fast ions in a solid density plasma created during the absorption of each femtosecond laser pulse.


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