Surface enhanced Raman scattering has been investigated from rhodamine 6G molecules embedded in polymethyl methacrylate () and coated on one-dimensional and two-dimensional gold-dielectric gratings fabricated by laser interference lithographically. The Raman signals from these plasmonic templates are 200 to 400 times larger than the signal from coated on plain gold films. The enhancement of the Raman signal varies almost periodically with the period of the grating. Finite-difference time-domain simulations show that large electromagnetic near fields occur at the metallic edges due to the resonant excitation of localized surface plasmon of the gold patches by the pump laser. These give rise to large enhancements of the Raman signal. The dependence on period is due to the combined effects of the localized surface plasmon and the periodic grating that couples the pump laser to the surface plasmon polariton.
© 2011 Optical Society of AmericaFull Article | PDF Article
Askin Kocabas, Gulay Ertas, S. Seckin Senlik, and Atilla Aydinli
Opt. Express 16(17) 12469-12477 (2008)
Haixi Zhang and Ho-Pui Ho
Opt. Express 17(23) 21159-21168 (2009)
Jonas Beermann, Sergey M. Novikov, Ole Albrektsen, Michael G. Nielsen, and Sergey I. Bozhevolnyi
J. Opt. Soc. Am. B 26(12) 2370-2376 (2009)