Compact optical circulator with three ports

A compact optical circulator with three ports, positioned between a dual-core collimator and a single-core collimator, wherein a light beam emitted from the dual-core collimator is input at the first port and is transmitted to the single-core collimator via the second port, and a light beam emitted from the single-core collimator is input at the second port and is transmitted to the dual-core collimator via the third port, the compact optical circulator with three ports comprising:

• a propagation director coupling the light beam emitted from the dual-core collimator to the first port of the circulator and the light beam emitted from the third port of the circulator to the dual-core collimator;
• a first birefringent device including a first optical axis, and having a function of splitting a light beam into two orthogonal polarized beams and combining two orthogonal polarized beams together;
• a second birefringent device including a second optical axis, and shifting two polarized beams entering the second birefringent device according to the second optical axis;
• a third birefringent device including a third optical axis, and having a function of splitting a light beam into two orthogonal polarized beams and combining two orthogonal polarized beams together;
• a first polarization rotator including a pair of non-reciprocal polarizing-rotating devices, positioned between the first and second birefringent devices to change the polarization of the polarized beam;
• and
• a second polarization rotator including a pair of non-reciprocal polarizing-rotating devices, positioned between the second and third birefringent devices to change the polarization of the polarized beam.

A compact optical circulator with three ports, positioned between a dual-core collimator and a single-core collimator, wherein a light beam emitted from the dual-core collimator is input at the first port and is transmitted to the dual-core collimator via the second port, and a light beam emitted from the dual-core collimator is input at the second port and is transmitted to the single-core collimator via the third port, the compact optical circulator with three ports comprising:

• a propagation director coupling the light beam emitted from the dual-core collimator to the first port of the circulator and the light beam emitted from the third port of the circulator to the dual-core collimator;
• a first birefringent device including a first optical axis, and having a function of splitting a light beam into two orthogonal polarized beams and combining two orthogonal polarized beams together;
• a second birefringent device including a second optical axis, and shifting two polarized beams entering the second birefringent device according to the second optical axis;
• a third birefringent device including a third optical axis, and having a function of splitting a light beam into two orthogonal polarized beams and combining two orthogonal polarized beams together;
• a first polarization rotator including a pair of non-reciprocal polarizing-rotating devices and a reciprocal polarizing-rotating device, positioned between the first and second birefringent devices to change the polarization of the polarized beam;
• a second polarization rotator including a pair of non-reciprocal polarizing-rotating devices and a reciprocal polarizing-rotating device, positioned between the second and third birefringent devices to change the polarization of the polarized beam;
• and
• a reflective compensator positioned between the non-reciprocal polarizing-rotating device and the reciprocal polarizing-rotating device of the second polarization rotator and having functions of reflecting the beams from the first port and passing the beams from the second port.

A compact optical circulator with three ports, positioned between a dual-core collimator and a single-core collimator, wherein a light beam emitted from the dual-core collimator is input at the first port and is transmitted to the dual-core collimator via the second port, and a light beam emitted from the dual-core collimator is input at the second port and is transmitted to the single-core collimator via the third port, the compact optical circulator with three ports comprising:

• a propagation director coupling the light beam emitted from the dual-core collimator to the first port of the circulator and the light beam emitted from the third port of the circulator to the dual-core collimator;
• a first birefringent device including a first optical axis, and having a function of splitting a light beam into two orthogonal polarized beams and combining two orthogonal polarized beams together;
• a second birefringent device including a second optical axis, and shifting two polarized beams entering the second birefringent device according to the second optical axis;
• a third birefringent device including a third optical axis, and having a function of splitting a light beam into two orthogonal polarized beams and combining two orthogonal polarized beams together;
• a first polarization rotator including a pair of non-reciprocal polarizing-rotating devices and is positioned between the first and second birefringent devices to change the polarization of the polarized beam;
• a second polarization rotator including a pair of non-reciprocal polarizing-rotating devices and is positioned between the second and third birefringent devices to change the polarization of the polarized beam;
• and
• a reflective compensator positioned between the non-reciprocal polarizing-rotating device and the reciprocal polarizing-rotating device of the second polarization rotator and having functions of reflecting the beams from the first port and passing the beams from the second port.