14 September 1998 Wavelength-dependent modification of insulator surfaces by a picosecond infrared free-electron laser
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Proceedings Volume 3343, High-Power Laser Ablation; (1998) https://doi.org/10.1117/12.321535
Event: High-Power Laser Ablation, 1998, Santa Fe, NM, United States
Abstract
Ultrashort-pulse lasers are at an increasing rate being used for laser-induced surface modification of insulators, including ablation. Ti:sapphire chirped-pulse amplifier systems, with fundamental wavelengths in the near infrared, can produce efficient ablation and other desirable surface modifications with little collateral damage because the laser energy is deposited on a time scale much shorter than thermal diffusion times. Little is known, however, about how ultrashort pulses interact with insulators at wavelengths in the vibrational infrared. This paper describes surface modifications achieved by picosecond laser irradiation in the 2 - 10 micrometer range. The laser source was a tunable, free- electron laser (FEL) with 1-ps micropulses spaced 350 ps apart in a macropulse lasting up to 4 microseconds, with an average power of up to 3 W. This unusual pulse structure makes possible novel tests of the dependence on fluence and intensity, as well as the effects of resonant vibrational excitation. As model materials systems, we studied calcium carbonate, its isoelectronic cousin sodium nitrate, and fused silica. Particularly intriguing are surface modifications achieved by tuning the laser into vibrational resonances of the target materials, or by tailoring the energy content of the pulse. The mechanisms underlying these effects, and their implications for materials-modification strategies, are discussed.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
David R. Ermer, Richard F. Haglund, Michael R. Papantonakis, Hee K. Park, Oguz Yavas, "Wavelength-dependent modification of insulator surfaces by a picosecond infrared free-electron laser", Proc. SPIE 3343, High-Power Laser Ablation, (14 September 1998); doi: 10.1117/12.321535; https://doi.org/10.1117/12.321535
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