Al-induced tunable surface plasmon resonance of Ag thin film by laser irradiation

Nd:YAG fiber pulsed laser irradiation was employed to tune the localized surface plasmon resonance (LSPR) properties of a single layer of Ag film and Ag/Al bilayer film in this letter. The LSPR wavelength of both films was realized: the tunability in wavelength shift and intensity by varying the laser scan speeds. Compared with the as-irradiated Ag film with limited LSPR wavelength shift and weak intensity, the Al buffer layer has the effects of enhancing the LSPR intensity, widening both the LSPR peak and wavelength shift, suppressing the interband absorption peak and improving the surface enhanced Raman scattering (SERS) performance of the Ag film.