The fabrication of ordered nanoporous metal films based on high field anodic alumina and their selected transmission enhancement.

A two-step high field anodization and a controllable barrier layer removing process have been used for the fabrication of porous anodic alumina (PAA) with different morphologies. Based on the PAAs, porous noble metal films with widely tunable pore size and inter-pore distance have been realized by a simple sputtering method. Their morphology and optical properties were studied with a field-emission scanning electron microscope, and ultraviolet and ultraviolet-visible spectrophotometers. An enhanced light transmission of the nanoporous metal films was detected. The transmissivity of a normal incidence light can be enhanced over ten times within a certain selected wavelength range. The intensity and position of the transmission peak depend on the morphology and porosity of the metal films.