Optical isolator.

摘要

A high quality small-sized polarization independent optical isolator for use in an optical fiber communication system, wherein a pair of magneto-optical elements (28,29) having Faraday rotation angle of 45 +/- 5 are contained in permanent magnets (30,31) and arranged between a pair of birefringent crystal plates (24,25) for splitting and combining an optical path of a laser light, and two polarizers (26,27) arranged in parallel as being bounded on the midpoint of separated optical paths are interposed between the pair of magneto-optical elements, whereby a degree of worsening the optical isolation can be kept minimum against variations of an environmental temperature and wave length.