Phase change mechanisms during femtosecond laser pulse train ablation of nickel thin films

2009 ◽  
Vol 106 (6) ◽  
pp. 064906 ◽  
Author(s):  
Xin Li ◽  
Lan Jiang ◽  
Hai-Lung Tsai
Keyword(s):  
Thin Films ◽  
Laser Pulse ◽  
Femtosecond Laser ◽  
Phase Change ◽  
Femtosecond Laser Pulse ◽  
Pulse Train ◽  
Nickel Thin Films ◽  
Change Mechanisms

Modeling of Ultrafast Phase Change Processes in a Thin Metal Film Irradiated by Femtosecond Laser Pulse Trains

2009 ◽  
Author(s):  
Jing Huang ◽  
Yuwen Zhang ◽  
J. K. Chen ◽  
Mo Yang
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Phase Change ◽  
Femtosecond Laser Pulse ◽  
Pulse Train ◽  
Ultrashort Laser Pulses ◽  
Maximum Temperature ◽  
Change Processes ◽  
Free Standing ◽  
Pulse Trains

Ultrashort laser pulses can be generated in the form of a pulse train. In this paper, the ultrafast phase change processes of a 1-μm free-standing gold film irradiated by femtosecond laser pulse trains are simulated numerically. A two-temperature model coupled with interface tracking method is developed to describe the ultrafast melting, vaporization and resolidification processes. To deal with the large span in time scale, variable time steps are adopted. A laser pulse train consists of several pulse bursts with a repetition rate of 0.5∼1 MHz. Each pulse burst contains 3∼10 pulses with an interval of 50 ps ∼ 10 ns. The simulation results show that with such a configuration, to achieve the same melting depth, the maximum temperature in the film decreases significantly in comparison to that of a single pulse. Although the total energy depositing on the film will be lifted, more energy will be transferred into the deeper part, instead of accumulating in the sub-surface layer. This leads to lower temperature and temperature gradient, which is favorable in laser sintering and laser machining.

Modeling of Ultrafast Phase Change Processes in a Thin Metal Film Irradiated by Femtosecond Laser Pulse Trains

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
Jing Huang ◽  
Yuwen Zhang ◽  
J. K. Chen ◽  
Mo Yang
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Phase Change ◽  
Femtosecond Laser Pulse ◽  
Pulse Train ◽  
Subsurface Layer ◽  
Maximum Temperature ◽  
Change Processes ◽  
Free Standing ◽  
Pulse Trains

Ultrashort laser pulses can be generated in the form of a pulse train. In this paper, the ultrafast phase change processes of a 1 μm free-standing gold film irradiated by femtosecond laser pulse trains are simulated numerically. A two-temperature model coupled with interface tracking method is developed to describe the ultrafast melting, vaporization, and resolidification processes. To deal with the large span in time scale, variable time steps are adopted. A laser pulse train consists of several pulse bursts with a repetition rate of 0.5–1 MHz. Each pulse burst contains 3–10 pulses with an interval of 50 ps–10 ns. The simulation results show that with such configuration, to achieve the same melting depth, the maximum temperature in the film decreases significantly in comparison to that of a single pulse. Although the total energy depositing on the film will be lifted, more energy will be transferred into the deeper part, instead of accumulating in the subsurface layer. This leads to lower temperature and temperature gradient, which is favorable in laser sintering and laser machining.

Femtosecond laser pulse-train induced breakdown in fused silica: the role of seed electrons

2014 ◽  
Vol 47 (43) ◽  
pp. 435105 ◽  
Author(s):  
Kaihu Zhang ◽  
Lan Jiang ◽  
Xin Li ◽  
Xuesong Shi ◽  
Dong Yu ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Pulse Train ◽  
Fused Silica

CONTROLLING ABOVE-THRESHOLD DISSOCIATION BRANCHING RATIOS OF HD+ WITH FEMTOSECOND LASER PULSE TRAIN

2012 ◽  
Vol 11 (04) ◽  
pp. 709-721 ◽  
Author(s):  
QIAN-ZHEN SU ◽  
JIE YU ◽  
KAI-JUN YUAN ◽  
SHU-LIN CONG
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Pulse Train ◽  
Branching Ratio ◽  
Branching Ratios ◽  
Pulse Number ◽  
Molecular Ions ◽  
Quantum Wave ◽  
Energy Dependent

Above-threshold dissociation (ATD) process of the molecular ions HD+ steered by a femtosecond laser pulse train (LPT) is investigated theoretically using the time-dependent quantum wave packet method. Energy-dependent distributions of ATD fragments are analyzed by using an asymptotic-flow expression in the momentum space. It is found that fragment kinetic energy spectra shift to low energy region with increasing pulse number of LPT. The photofragment branching ratio between the 1sσg and 2pσu dissociation channels is sensitive to the pulse number of LPT. The momentum distribution of the ATD fragments is discussed in detail.

Femtosecond laser pulse induced damage in thin films

2006 ◽  
Author(s):  
Haiyi Sun ◽  
Tianqing Jia ◽  
Xiaoxi Li ◽  
Chengbin Li ◽  
Donghai Feng ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse

Femtosecond laser pulse train effect on Doppler profile of cesium resonance lines

2006 ◽  
Vol 41 (3) ◽  
pp. 447-454 ◽  
Author(s):  
N. Vujičić ◽  
S. Vdović ◽  
D. Aumiler ◽  
T. Ban ◽  
H. Skenderović ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Pulse Train ◽  
Doppler Profile

Observation of carrier dynamics in CdO thin films by excitation with femtosecond laser pulse

2003 ◽  
Vol 445 (2) ◽  
pp. 182-185 ◽  
Author(s):  
Ken-ichi Kawamura ◽  
Keisuke Maekawa ◽  
Hiroshi Yanagi ◽  
Masahiro Hirano ◽  
Hideo Hosono
Keyword(s):  
Thin Films ◽  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Carrier Dynamics ◽  
Cdo Thin Films
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