LAUSR

We systematically investigate the optical properties of silver films to clear up the inconsistency in the published values of the dielectric function of silver. The silver films were deposited on mica by using a facing target sputtering system, which yielded a large area single crystal of silver suitable for the fabrication of high-finesse plasmonic devices and metamaterials. We confirmed that wide variations in the optical properties of silver were associated with the overall quality of the silver films including crystal structure, thickness, and surface roughness. The quality factor of the surface plasmon polaritons calculated for the obtained single crystal is 5 × 103, which is about five times higher than that for polycrystalline films.