1. A polarization beam splitter comprising: at least six prisms assembled together to form a single solid component consisting of a pair of substantially-orthogonal diagonal interfaces each formed by a combination of two or more prism surfaces; wherein: the solid component has at least four light entrance or exit surfaces, at least two of the light entrance or exit surfaces forming a step; at least one prism has a non-triangular cross-sectional shape; and at least one surface of a prism that forms a portion of an individual diagonal interface has a polarization beam splitting material disposed thereon.