POLARIZATION-INDEPENDENT OPTICAL ISOLATOR

摘要

[Object] To provide a polarization independent optical isolator enabling downsizing of a Faraday element and a magnet. [Solving means] The polarization independent optical isolator comprises: a pair of wedge-shaped birefringent crystal plates (1, 2) provided in an optical path; and a Faraday element (30) made of a paramagnetic body and provided in the optical path between the wedge-shaped birefringent crystal plates. The pair of wedge-shaped birefringent crystal plates have inclined light-transmitting surfaces parallel to each other and non-inclined light-transmitting surfaces parallel to each other. The non-inclined light-transmitting surfaces are disposed to face the Faraday element. The polarization independent optical isolator is characterized in that: the paramagnetic body constituting the Faraday element has such a parallelogrammic cross section that light incident-emitting surfaces of the paramagnetic body are not parallel to the non-inclined light-transmitting surfaces of the pair of wedge-shaped birefringent crystal plates; and a right-angled portion (100) of each of the wedge-shaped birefringent crystal plates and a corresponding obtuse-angled portion (31) of the Faraday element are disposed on the same side with respect to an optical path central axis.