This invention discloses an optical circulator. The optical circulator includes a first set of optical components having a birefringent crystal, a pair of half wave plates and the Faraday rotator to separate and then polarize the light beam into projection-direction ready polarization components. These projection-direction ready polarization components are suitable for entering into a projection-direction optical-processing-optical device, e.g., a Wollaston prism, to generate the projecting-to-exit-port beam components. The circulator then employs a set of reciprocal components of the first set of optical components to carry out reciprocal polarization rotations and beam component merging processes to transmit an output beam to the exit port by projecting the beam components and the merged beam along the projecting-to-exit port direction.