Probing ultra-thin amorphous carbon films by means of nanometric silver islands

The optical properties of silver island films in ultra-thin sandwich sample s are investigated. The samples essentially represent a three-layer system, where an amorphous carbon layer is embedded between two amorphous silicon films. The carbon layer itself contains nanometric silver islands. Due to t he spatially close carbon-silicon interface, a change in the carbon film th ickness affects the resonance frequency of the surface plasmon excitation i n the silver islands. In this way, the fraction of the optical loss that is caused by the silver islands may be shifted in the wavelength range betwee n 900 and 570 nm. (C) 2000 Elsevier Science B.V. All rights reserved.