Patent ID: 6026202
Filing Date: 2000-02-15
Classification: G02B,G02F

Abstract:
A miniature three-port optical circulator, the optical circulator having an optical axis, and comprising:a first input/output (I/O) port including the following components arranged in order along the optical axis:a light coupling assembly, comprising:a capillary having a bore and an end, the end being perpendicular to the bore, the bore having a diameter; andtwo optical fibres secured side-by-side in the bore of the capillary, the optical fibres each having a diameter of one half of the diameter of the bore and including a core, the cores of the optical fibres being separated from one another in a separation direction by a separation distance,a first walk-off crystal adjacent the light coupling assembly, the first walk-off crystal having a first walk-off direction perpendicular to the separation direction, anda split polarization rotator adjacent the first walk-off crystal, the split polarization rotator having a positive half and a negative half and being located so that polarization components of the light beams deviated by the first walk-off crystal pass through a different one of the positive half and the negative half from polarization components not deviated by the first walk-off crystal;a second I/O port complementary to the first I/O port; anda second walk-off crystal located between the first I/O port and the second I/O port, the second walk-off crystal having a second walk-off direction perpendicular to the first walk-off direction, and having a walk-off distance equal to the separation distance.