scholarly journals Nonlinear enhancement of femtosecond laser ablation efficiency by hybridization with nanosecond laser

2006 ◽  
Vol 14 (20) ◽  
pp. 9544 ◽  
Author(s):  
J. S. Yahng ◽  
B. H. Chon ◽  
C. H. Kim ◽  
S. C. Jeoung ◽  
H. R. Kim
2012 ◽  
Vol 30 (3) ◽  
pp. 473-479 ◽  
Author(s):  
Mohamed E. Shaheen ◽  
Brian J. Fryer

AbstractThe interaction of near infrared femtosecond laser pulses with a Cu based alloy (brass) in ambient air at atmospheric pressure and under different laser conditions was investigated. The effects of laser fluence and number of pulses on surface morphology and ablation rate were studied using scanning electron microscopy (SEM) and optical microscopy. Ablation rates were found to rapidly increase from 83 to 604 nm/pulse in the fluence range 1.14–12.21 J/cm2. At fluence >12.21 J/cm2, ablation rates increased slowly to a maximum (607 nm/pulse at 19.14 J/cm2), and then decreased at fluence higher than 20.47 J/cm2 to 564 nm/pulse at 24.89 J/cm2. Large amounts of ablated material in a form of agglomerated fine particles were observed around the ablation craters as the number of laser pulses and fluence increased. The study of surface morphology shows reduced thermal effects with femtosecond laser ablation in comparison to nanosecond laser ablation at low fluence.


2000 ◽  
Author(s):  
Mengqi Ye ◽  
Costas P. Grigoropoulos

Abstract Femtosecond laser ablation of titanium and silicon samples has been studied via time-of-flight (TOF), emission spectroscopy and microscopy measurement. Laser pulses of around 100 fs (FWHM) at λ = 800 nm were delivered by a Ti:sapphire femtosecond laser system. A vacuum chamber with a base pressure of 10−7 torr was built for ion TOF measurement. These ion TOF spectra were utilized to determine the velocity distribution of the ejected ions. While nanosecond laser ablation typically generates ions of a few tens of eV, femtosecond laser irradiation even at moderate energy densities can produce energetic ions with energies of up to a few keV. The most probable energy of these fast ions is proportional to the laser fluence. The structure and number of peaks of the TOF spectra varies with the laser fluence. Images of plume emission were captured by an intensified CCD (ICCD) camera. The plume emission spectrum was analyzed by a spectrometer. Laser ablated craters were measured by an interferometric microscope and a scanning electron microscope (SEM). Ablation yield was expressed as a function of laser fluence, and number of shots.


2019 ◽  
Vol 51 (9) ◽  
pp. 797-807 ◽  
Author(s):  
Sarathkumar Loganathan ◽  
Soundarapandian Santhanakrishnan ◽  
Ravi Bathe ◽  
Muthukumaraswamy Arunachalam

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5544
Author(s):  
Niusha Lasemi ◽  
Günther Rupprechter ◽  
Gerhard Liedl ◽  
Dominik Eder

Scanning electron microscopy (SEM) and profilometry of the crater morphology and ablation efficiency upon femtosecond laser ablation of Au-coated Ni targets in various fluids revealed a pronounced dependence on the ablation medium. For ethanol, a sufficient ablation efficiency was obtained, whereas for 2-butanol a higher efficiency indicated stronger laser–target interaction. Hierarchical features in the crater periphery pointed to asymmetrical energy deposition or a residual effect of the Coulomb-explosion-initiating ablation. Significant beam deviation in 2-butanol caused maximum multiple scattering at the crater bottom. The highest values of microstrain and increased grain size, obtained from Williamson–Hall plots, indicated the superposition of mechanical stress, defect formation and propagation of fatigue cracks in the crater circumference. For n-hexane, deposition of frozen droplets in the outer crater region suggested a femtosecond-laser-induced phase explosion. A maximum ablation depth occurred in water, likely due to its high cooling efficiency. Grazing incidence micro X-ray diffraction (GIXRD) of the used target showed residual carbon and partial surface oxidation. The produced nanoparticle colloids were examined by multiangle dynamic light scattering (DLS), employing larger scattering angles for higher sensitivity toward smaller nanoparticles. The smallest nanoparticles were obtained in 2-butanol and ethanol. In n-hexane, floating carbon flakes originated from femtosecond-laser-induced solvent decomposition.


2015 ◽  
Vol 20 (2) ◽  
pp. 028004 ◽  
Author(s):  
Hu Chen ◽  
Jing Liu ◽  
Hong Li ◽  
Wenqi Ge ◽  
Yuchun Sun ◽  
...  

2012 ◽  
Vol 20 (9) ◽  
pp. 9763 ◽  
Author(s):  
Yuechen Jia ◽  
Ningning Dong ◽  
Feng Chen ◽  
Javier R. Vázquez de Aldana ◽  
Sh. Akhmadaliev ◽  
...  

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