A broadband wire grid polarizer for the visible spectrum has a plurality of elongated elements supported on a substrate. A region having a lower refractive index than the refractive index of the substrate is disposed between the elements and the substrate to reduce the longest wavelength at which resonance occurs. The region may comprise a plurality of ribs extending from the substrate and supporting the elements. The ribs may be formed by etching slots into the substrate using the elements as a mask. The region may also comprise at least one layer of dielectric film. In addition the region may be comprise ribs extending from the surface, each having at least one layer of dielectric film disposed thereon.