Investigation of transmission of Au films with nanohole arrays created by nanosphere lithography

In this report, we present experimental results of transmittance through nanohole arrays created onto Au films on glass substrates. 110-nm-thick Au films with arrays of nanoholes were fabricated by using self-assembled polystyrene spheres, of which the diameters were reduced to designed values on site by dry etching, as a template. Transmission spectra of the nanostructured Au films show strong enhancement (more than 45%) in a wide range from 300 nm to 1600 nm, the measurement wavelength range. Besides a peak observed at around 500 nm in all spectra, a wider peak on the longer wavelength side was observed, which shifted to longer wavelength when periodicities of the hole arrays were increased.