Patent ID: 7173762

Claim:
An optical isolator core, comprising: a first polarizer having a wedge shape and configured to receive incident light traveling along a path and refract the incident light into o-rays and e-rays, wherein said first polarizer has an optic axis angle of approximately +45Â° or âˆ’45Â°; a rotator disposed along the path and configured to rotate the polarization planes of the o-rays and e-rays; a second polarizer having a wedge shape and disposed along the path after the rotator, the second polarizer having an optic axis angle of approximately 0Â° or 90Â° apart from an optical axis of the first polarizer, and the first and second polarizers having approximately the same wedge angle; and a correction element of birefringent material, disposed along the path and adjacent to a diagonal face of the second polarizer, having a length and an optic axis angle, wherein the length and the correction element optic axis angle compensate for a differential group delay and walk-off introduced by the first and the second polarizers, wherein the correction element includes an optical plane in which said o-rays and said e-rays travel, wherein said optical plane is perpendicular to said optic axis of said second polarizer, and an input face of the correction element being parallel to an input face of the second polarizer such that the optical plane of the correction element is perpendicular to the optic axis of second polarizer.