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DE2005836676

Publication Date	2005
Personal Author	Zong, X.; Mao, X.; Greif, R.; Russo, R. E.
Page Count	14
Abstract	Femtosecond laser ablation of silicon in air was studied and compared with nanosecond laser ablation at ultraviolet wavelength (266 nm). Laser ablation efficiency was studied by measuring crater depth as a function of pulse number. For the same number of laser pulses, the fs-ablated crater was about two times deeper than the ns-crater. The temperature and electron number density of the pulsed laser-induced plasma were determined from spectroscopic measurements. The electron number density and temperature of fs-pulse plasmas decreased faster than ns-pulse plasmas due to different energy deposition mechanisms. Images of the laser-induced plasma were obtained with femtosecond time-resolved laser shadowgraph imaging. Plasma expansion in both the perpendicular and the lateral directions to the laser beam were compared for femtosecond and nanosecond laser ablation.
Keywords	Laser-induced plasma Shock wave Electrons Plasma Plasma expansion Silicon Laser ablation Femtosecond pulses
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Berkeley National Lab., CA.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200520

Ultraviolet Femtosecond and Nanosecond Laser Ablation of Silicon: Ablation Efficiency and Laser-Induced Plasma Expansion.

Ultraviolet Femtosecond and Nanosecond Laser Ablation of Silicon: Ablation Efficiency and Laser-Induced Plasma Expansion.
DE2005836676

Publication Date	2005
Personal Author	Zong, X.; Mao, X.; Greif, R.; Russo, R. E.
Page Count	14
Abstract	Femtosecond laser ablation of silicon in air was studied and compared with nanosecond laser ablation at ultraviolet wavelength (266 nm). Laser ablation efficiency was studied by measuring crater depth as a function of pulse number. For the same number of laser pulses, the fs-ablated crater was about two times deeper than the ns-crater. The temperature and electron number density of the pulsed laser-induced plasma were determined from spectroscopic measurements. The electron number density and temperature of fs-pulse plasmas decreased faster than ns-pulse plasmas due to different energy deposition mechanisms. Images of the laser-induced plasma were obtained with femtosecond time-resolved laser shadowgraph imaging. Plasma expansion in both the perpendicular and the lateral directions to the laser beam were compared for femtosecond and nanosecond laser ablation.
Keywords	Laser-induced plasma Shock wave Electrons Plasma Plasma expansion Silicon Laser ablation Femtosecond pulses
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Berkeley National Lab., CA.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200520