Polarized light separation element and optical reception device

Abstract

A polarization splitting device includes a substrate, and a polarization splitting layer having a structure element pattern including a plurality of structure elements each having two-fold rotational symmetry, and formed on an upper surface of the substrate. The polarization splitting layer splits first to sixth polarization components included in object light, and focuses respectively at first to sixth focal positions on a focal plane. The structure element pattern includes a first structure element pattern for focusing the first and second polarization components, a second structure element pattern for focusing the third and fourth polarization components, and a third structure element pattern for focusing the fifth and sixth polarization components, and a pattern constituted by a first structure element, a second structure element, and a third structure element is set as a unit pattern, and a plurality of unit patterns are two-dimensionally arranged.