Optical anisotropy of stretched gold island films: experimental results

Stretched gold island films with large optical anisotropy are demonstrated for the first time to our knowledge. The resonance absorption wavelength for polarization parallel to the stretching direction shifted from 0.54 to 0.95 microm by stretching a 9-nm-thick gold island film by five times, whereas the resonance wavelength shifted slightly to the shorter wavelength for perpendicular polarization. The origin of optical anisotropy is shown to come from an elongated island shape. Embedding of island films in a glass film is also shown to be necessary to produce the anisotropy in the stretching process.