Structural changes in fused silica after exposure to focused femtosecond laser pulses.
Using in situ Raman scattering in a confocal microscopy setup, we have observed changes in the network structure of fused silica after modifying regions inside the glass with tightly focused 800-nm 130-fs laser pulses at fluences of 5-200 J cm(-2). The Raman spectra show a large increase in the peaks at 490 and 605cm(-1), owing to 4- and 3-membered ring structures in the silica network, indicating that densification occurs after exposure to the femtosecond laser pulses. The results are consistent with the formation of a localized plasma by the laser pulse and a subsequent microexplosion inside the glass.
J W
JW
Chan
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T
Huser
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S
Risbud
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DM
Krol