| 摘要 |
An optical isolator utilizes a pair of polarization selective elements, as for example birefringent wedges, and all integral Faraday rotator aligned therewith to perform optical signal isolation without introducing the polarization mode dispersion inherent in conventional polarization independent optical isolators. Optical isolation is accomplished by passing a forward-directed optical signal through a first birefringent element which separates the optical signal into two orthogonal states. The two orthogonal polarization states exchange identities upon entering the second birefringent element from the Faraday rotation element and are again deflected by the second birefringent element so that they emerge from the second element parallel to each other and, having traveled the same optical path length, witllout any polarization mode dispersion. Both polarization states of the reverse propagating optical signal are sufficiently angularly deflected to avoid coupling with the optical signal path.
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