Composite films of Au and dielectric material (TiO2 and/or mixed ZnS-SiO2)
with a wide range of Au fractions were fabricated through a co-sputtering m
ethod utilizing a multi-target sputtering system. The optical absorption sp
ectra of these composite films demonstrated an absorption peak due to surfa
ce plasmon resonance of embedded Au nanoclusters. It was found that, depend
ing on the dielectric matrix, Au concentration, and post-deposition anneali
ng, the wavelength of the surface plasmon resonance of nanoclusters shifted
by 130 nm: from 550 to 680 nm. The third-order non-linear susceptibility c
hi ((3)) of these composite films, which also originates from field enhance
ment due to the surface plasmon resonance, demonstrated a corresponding var
iation. (C) 2000 Elsevier Science B.V. All rights reserved.