Abstract: There is provided an optical circulator (16) for bidirectional communication on a fiber optic communication transmission system. A reflection rhomb (17) includes a polarizing thin film (26) and an inclined, internally reflecting end surface (22). A first birefringent crystal (28) is disposed against the reflection rhomb (17). A quartz rotator (34) is disposed against the opposite side of the first birefringent crystal (28). A Faraday rotator (40) is disposed against the opposite side of the quartz rotator (34). A second birefringent crystal (46) is disposed against the opposite side of the Faraday rotator (40). The components of optical circulator (16) cooperate such that light transmitted into port 1 exits from port 2, and light transmitted into port 2 exits from port 3.