Optical polarizers based on gold nanowires fabricated using colloidal gold nanoparticles

We demonstrate optical polarization devices, consisting of gold nanowires, which are based on the strong polarization dependence of the particle plasmon resonance of the gold nanowires and the resonance of the waveguided grating structures. Using a layer of indium tin oxide underneath the gold nanowires as the waveguide, we achieved tunable polarization band-pass and band-suppression filters in the transmission and reflection configuration with a bandwidth less than 20 nm at full width at half maximum (FWHM) in the visible spectral range. Then, using side-input geometry for multiplying the absorption by the particle plasmon resonance, we achieved a strong band-suppression polarizer with an extinction ratio of up to 145. These polarization devices can be used directly in optical engineering, and potentially provide alternatives to conventional devices in some special applications. A simple solution-processible fabrication technique enables high quality and large area (>10 × 10 mm(2)) production of these polarizers.