Abstract: An optical isolator includes a first optical collimator, a first birefringent crystal, a Faraday rotator, a second birefringent crystal and a second optical collimator. The first and second collimators have the same structure and configuration. Each first and second collimator includes a ferrule, an optical fiber retained in the ferrule, and a collimating lens, all of which are secured in a tube. The first and second birefringent crystals are respectively fixed to the first and the second collimators. The Faraday rotator is stationed between the first and second collimators, and fixed onto an end of the first collimator. In assembly, the first and second collimators and the Faraday rotator are all secured in a stainless steel outer tube. The second collimator is rotated within the outer tube until correct relative alignment of optical axes of the birefringent crystals is attained.

Abstract: An optical isolator includes a first optical collimator, a first birefringent crystal, a Faraday rotator, a second birefringent crystal and a second optical collimator. The first and second collimators have the same structure and configuration. Each first and second collimator includes a ferrule, an optical fiber retained in the ferrule, and a collimating lens, all of which are secured in a tube. The first and second birefringent crystals are respectively fixed to the first and the second collimators. The Faraday rotator is stationed between the first and second collimators, and fixed onto an end of the first collimator. In assembly, the first and second collimators and the Faraday rotator are all secured in a stainless steel outer tube. The second collimator is rotated within the outer tube until correct relative alignment of optical axes of the birefringent crystals is attained.

Abstract: An optical isolator comprises a first collimator (10), an isolating unit (60), a second collimator (20) and an outer metallic holder (40). Each first and second collimator has a sleeve (12, 22), and the sleeve of the second collimator is longer than the sleeve of the first collimator. The isolating unit is stationed between the first and second collimators. The isolating unit comprises a first polarimeter (61), a polarized rotary crystal (62), a second polarimeter (63), and a magnetic ring (64). A length of the magnetic ring is slightly less than or equal to a combined length of the first and second polarimeters and the polarized rotary crystal. The magnetic ring is glued to an end surface of an inmost end of the sleeve of the second collimator. A subassembly of the first collimator, the isolating unit and the second collimator is received in the outer metallic holder.