Patent ID: 6590706
Filing Date: 2003-07-08
Classification: G02B,G02F

Abstract:
An optical circulator apparatus having a longitudinal axis and a first and third port positioned at a proximal end of the apparatus and a second port positioned at a distal end of the apparatus, said optical circulator comprising:a first dividing and combining element positioned adjacent the first and third port and adapted to divide a beam into two beams of orthogonal polarizations and to combine two beams of orthogonal polarizations into one beam; a compound polarization-dependent beam guiding element configured to transmit a beam in a predetermined direction responsive to a polarization orientation of the beam such that light from the first port is transmitted towards the second port and light from the second port is transmitted towards the third port; a second dividing and combining element positioned adjacent the second port and adapted to divide a beam into two beams of orthogonal polarizations and to combine two beams of orthogonal polarizations into one beam; a first imaging element positioned intermediate the first dividing and combining element and the beam guiding element; a second imaging element positioned intermediate the beam guiding element and the second dividing and combining element; and first and second reciprocal polarization rotators configured to render two orthogonal polarization vectors parallel or two parallel polarization vectors orthogonal, wherein the first imaging element is sandwiched between the first reciprocal polarization rotator and the beam guiding element and the second imaging element is sandwiched between the beam guiding element and the second reciprocal polarization rotator, and, wherein said beam guiding element comprises a modified Wollaston prism, or a modified Rochon prism.