Melting, Vaporization, and Resolidification in a Thin Gold Film Irradiated by Multiple Femtosecond Laser Pulses

Author(s):  
Yijin Mao ◽  
Yuwen Zhang ◽  
J. K. Chen

Melting, vaporization, and resolidification in a gold thin film subject to multiple femtosecond laser pulses are numerically studied in the framework of the two-temperature model. The solid-liquid phase change is modeled using a kinetics controlled model that allows the interfacial temperature to deviate from the melting point. The kinetics controlled model also allows superheating in the solid phase during melting and undercooling in the liquid phase during resolidification. Superheating of the liquid phase caused by nonequilibrium evaporation of the liquid phase is modeled by adopting the wave hypothesis, instead of the Clausius–Clapeyron equation. The melting depth, ablation depth, and maximum temperature in both the liquid and solid are investigated and the result is compared with that from the Clausius–Clapeyron equation based vaporization model. The vaporization wave model predicts a much higher vaporization speed, which leads to a deeper ablation depth. The relationship between laser processing parameters, including pulse separation time and pulse number, and the phase change effect are also studied. It is found that a longer separation time and larger pulse number will cause lower maximum temperature within the gold film and lower depths of melting and ablation.

2007 ◽  
Vol 539-543 ◽  
pp. 1951-1954 ◽  
Author(s):  
Tomokazu Sano ◽  
Kengo Takahashi ◽  
Akio Hirose ◽  
Kojiro F. Kobayashi

Dependence of the femtosecond laser ablation depth on the laser pulse energy was investigated for Zr55Al10Ni5Cu30 bulk metallic glass. Investigation of the femtosecond laser ablation of bulk metallic glasses has not been reported. Femtosecond laser pulses (wavelength of 800 nm, pulse width of 100 fs, pulse energies of 2 – 900 μJ) were focused and irradiated on the polished surface of metals in air. The ablation depth of the metallic glass is deeper than that of its crystallized metal at a pulse energy in the strong ablation region. We suggest that the energy loss at grain boundaries of hot electrons which is accelerated by the laser electric field influence the ablation depth in the strong ablation region.


ACS Photonics ◽  
2014 ◽  
Vol 1 (9) ◽  
pp. 833-839 ◽  
Author(s):  
Ann-Katrin U. Michel ◽  
Peter Zalden ◽  
Dmitry N. Chigrin ◽  
Matthias Wuttig ◽  
Aaron M. Lindenberg ◽  
...  

JETP Letters ◽  
2008 ◽  
Vol 88 (4) ◽  
pp. 261-263
Author(s):  
B. N. Mironov ◽  
S. A. Aseev ◽  
V. S. Makin ◽  
S. V. Chekalin ◽  
V. S. Letokhov

2005 ◽  
Author(s):  
Guangjun Zhang ◽  
Donghong Gu ◽  
Xiongwei Jiang ◽  
Qingxi Chen ◽  
Fuxi Gan

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