An optical isolator includes a non-reciprocal combination-device and a reflector. The non-reciprocal combination-device has a principal direction and includes a first birefringent wedge, a second birefringent wedge, and a non-reciprocal rotating element. The non-reciprocal rotating element can be a Faraday rotator. The reflector is positioned proximate to the second birefringent wedge, for reflecting light exiting from the non-reciprocal combination-device in the principal direction to reenter the non-reciprocal combination-device in a reverse principal direction. The optical isolator can include a lens that is optically coupled to the first wedge. The optical isolator can include a capillary for holding an input PM optical fiber and an output PM optical fiber. The optical isolator can also include a capillary for holding at least two input PM optical fibers and an output optical fiber.