A fiber optical circulator in which is a light beam is fed from a fiber of a first port in a dual core glass capillary, then collimated before being passed to a birefringent crystal wherein the light beam is divided into two orthogonal components o and e with a displacement. The State of Polarization (SOP) of components then are changed into the same, perpendicular to the incident plane of the birefringent crystal prism by the group of Faraday Rotator and two Half-Wave Plates (HWP) that have different optical axis orientation and cover o and e components respectively. Then the light components with the same SOP pass into a birefringent prism where they receive angle correction to meet receiving requirement in incident angle for the fiber of port 2 without displacement due to their SOP. This is followed by a second group of HWP and Faraday Rotator that changes the SOP of two components back to orthogonal. The light beam of components then pass into the second birefringent crystal which combines the o and e components together and pass through collimator lens, and are received by optical fiber of the second port. The optical path from the second port to the third port is similar to that described above. However, due to the non-reciprocal property of the Faraday Rotator, the SOP of the two light components from the second port will be in the incident plane of the crystal prism, therefore receive a displacement after the birefringent crystal prism. This displacement combined with angle correction allows the light from the second port is fed into the fiber of the third port. An alternative design uses a pair of glass prism and a plane crystal to replace the function of crystal prism in the preferred embodiment.