Femtosecond and Nanosecond Laser Fabricated Substrate for Surface-Enhanced Raman Scattering
We report a simple and repeatable method for fabricating a large-area substrate for surface-enhanced Raman scattering. The substrate was processed by three steps: (i)Â femtosecond (fs) laser micromachining and roughening, (ii)Â thin-film coating, and (iii)Â nanosecond laser heating and melting. Numerous gold nanoparticles of various sizes were created on the surface of the silicon substrate. The 3D micro-/nanostructures generated by the fs laser provide greater surface areas with more nanoparticles leading to 2 orders of magnitude higher of the enhancement factor than in the case of a flat substrate. Using an He-Ne laser with a 632.8-‰nm excitation wavelength, the surface-enhanced Raman scattering enhancement factor for Rhodamine 6G was measured up to 2Ã—107 .
A. Hamdorf et al., "Femtosecond and Nanosecond Laser Fabricated Substrate for Surface-Enhanced Raman Scattering," Optics Letters, Optical Society of America, Jan 2011.
The definitive version is available at http://dx.doi.org/10.1364/OL.36.003353
Mechanical and Aerospace Engineering
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