Ultraviolet femtosecond and nanosecond laser ablation of silicon: Ablation efficiency and laser-induced plasma expansion

Zeng, Xianzhong ; Mao, Xianglei ; Greif, Ralph ; Russo, Richard E.

Lawrence Berkeley National Laboratory

关键词: Plasma Expansion;    Wavelengths;    Air;    Ablation;    29 Energy Planning, Policy And Economy;   

DOI  :  10.2172/836676
RP-ID  :  LBNL--56159
RP-ID  :  AC03-76SF00098
RP-ID  :  836676

美国|英语

来源: UNT Digital Library

【 摘 要 】

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.