Broadband and wide field angle compensator

摘要

A rotatable compensator configured to transmit non-collimated light over a broad range of wavelengths, including ultraviolet, with a high degree of retardation uniformity across the aperture is presented. In one embodiment, a rotatable compensator includes a stack of four individual plates in optical contact. The two thin plates in the middle of the stack are made from a birefringent material and are arranged to form a compound, zeroth order bi-plate. The remaining two plates are relatively thick and are made from an optically isotropic material. These plates are disposed on either end of the compound, zeroth order bi-plate. The low order plates minimize the sensitivity of retardation across the aperture to non-collimated light. Materials are selected to ensure transmission of ultraviolet light. The optically isotropic end plates minimize coherence effects induced at the optical interfaces of the thin plates.

主权项

1. A parallel plate compensator, comprising:
a first birefringent plate having a front surface, a back surface, an optic axis oriented in a plane parallel to the front and back surfaces within a manufacturing tolerance, and a thickness of less than five hundred micrometers; a second birefringent plate having a front surface, a back surface, an optic axis oriented in a plane parallel to the front and back surfaces within the manufacturing tolerance, and a thickness of less than five hundred micrometers, wherein the first birefringent plate and the second birefringent plate are oriented such that the optic axis of the first birefringent plate is aligned approximately perpendicular to the optic axis of the second birefringent plate; and a first optically isotropic plate in optical contact with the front surface of the first birefringent plate, the optically isotropic plate having a thickness of at least five hundred micrometers, wherein a refractive index of the optically isotropic plate is within 15% of a mean refractive index of the first birefringent plate.