Patent ID: 8259393

Claim:
An optical element, comprising: a support plate comprising optically active material having an optic axis, where the optically active material rotates a polarization direction of linearly polarized light propagating through the optically active material in a direction parallel to the optic axis; at least two planar-parallel portions supported by the support plate, each of the at least two planar-parallel portions comprising optically active material having an optic axis, where the optically active material of each planar-parallel portion rotates a polarization direction of linearly polarized light propagating through the optically active material in a direction parallel to the optic axis of the optically active material of the respective planar-parallel portion, wherein: there exists a first path and a second path of light through the optical element, the first path traversing the support plate and a first of the planar-parallel portions parallel to the optic axis of the optically active material of the first planar-parallel portion, and the second path traversing the support plate and a second of the planar-parallel portions parallel to the optic axis of the optically active material of the second planar-parallel portion; when a first linearly polarized light ray passes through the optical element along the first path, a plane of oscillation of the first linearly polarized light ray is rotated by a first angle; and when a second linearly polarized light ray passes through the optical element along the second path, a plane of oscillation of the second linearly polarized light ray is rotated by a second angle different from the first angle.