Article

Femtosecond and nanosecond laser fabricated substrate for surface-enhanced Raman scattering.

Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, Missouri 65409, USA.
Optics Letters (Impact Factor: 3.18). 09/2011; 36(17):3353-5. DOI: 10.1364/OL.36.003353
Source: PubMed

ABSTRACT 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) femtosecond (fs) laser micromachining and roughening, (ii) thin-film coating, and (iii) 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 2×10(7).

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