Patent ID: 8687151

Claim:
A polarization element comprising: a substrate; a plurality of metal protruding sections formed on the substrate in a striped manner in a plan view; and a heat radiation section formed on a top portion of each of the protruding sections, wherein each of the heat radiation sections has a concave section and a convex section that includes a first heat radiation section formed on a surface of the top portion of each of the protruding sections and a second heat radiation section formed on the first heat radiation section, each of the heat radiation sections are entirely separated by a gap from adjacent heat radiation sections, the gap being operable to release heat stored therein; and all of the first heat radiation sections are tilted in a first direction toward one of adjacent ones of the protruding sections with respect to the surface of the top portion, and all of the second heat radiation sections are tilted in a second and opposite direction toward the other of adjacent ones of the protruding sections with respect to the surface of the top portion.