of the transparent material 45 increases the opl of one polarized beam having shorter opl accordingly the reflective compensator 106 b of the second embodiment of the invention can solve the problem of opd as well referring to fig5 a 5b and 6 b the area of the reflective compensator 106 b is half of the cross sectional area of the optical circulator 2000 and then the light beam received from the second port 20 can travel through the reflective compensator 106 b in the third example the compact optical circulator with three ports includes a dual core collimator a propagation director a first birefringent crystal a first polarization rotator a second birefringent crystal a second polarization rotator a reflective compensator a third birefringent crystal and a single core collimator the first and second polarization rotators respectively have a faraday rotator and a half wave plate and the reflective compensator is positioned between the faraday rotator and the half wave plate of the second polarization rotator 0058 fig7 a schematically shows the spatial location and the polarization of the light beam traveling from the first port to the second port in the compact optical circulator of the third example each arrow respectively shows the projecting component of the optical axis of each birefringent crystal in the x y plane while a light beam emitted from the first fiber 11 of the dual core collimator 1 is received by the first port 10 of the circulator 2000 the polarization of the light beam is random when the light beam travels through the first birefringent crystal 101 the light beam is split into two polarized beams according to the arrow representing the walk off characteristic of the first birefringent crystal 101 wherein one is an e.