An optical isolator has a sleeve with a longitudinal channel, a pair of optical fibers in the longitudinal channel, a first, second and third birefringent crystals, a GRIN lens, a Faraday rotator and a mirror element. The first birefringent crystal covers the end facet of one of the pair of optical fibers, and the second and third birefringent crystals cover the end facet of the other of the pair of optical fibers. The GRIN lens has first and second end faces with the first end face proximate the first, second and third birefringent crystals. The Faraday rotator is located between the mirror element and the second end face of the GRIN lens. Light in one direction from a first optical fiber of the pair passes through, and back from, the first, second and third birefringent crystals, the GRIN lens, the Faraday rotator and the mirror element into a second optical fiber of the pair. On the other hand, light in a reverse direction from the second optical fiber passes through, and back from, the first, second and third birefringent crystals, the GRIN lens, the Faraday rotator and the mirror element, but not into the first optical fiber so that an optical isolation function is achieved. Multiple optical isolators may be obtained with multiple pairs of optical fibers fixed in the channel of the ferrule.
展开▼
