Optical circulator

Claim 1

AN OPTICAL CIRCULATOR HAVING AT LEAST THREE PORTS COMPRISING FIRST IREFRINGENT MEANS FOR TRANSMITTING INCIDENT ELECTROMAGNETIC WAVE ENERGY OF ORTHOGONAL POLARIZATIONS THROUGH DIFFERENT SURFACES THEREOF, SAID FIRST BIREFRINGENT MEANS COMPRISING FIRST AND SECOND PRISMS OF GIVEN REFRACTIVE INDEX WHICH ARE SEPARATED BY A GAP OF REFRACTIVE INDEX LESS THAN SAID GIVEN INDEX AND WHICH HAVE OPTIC AXIS DIRECTIONS WHICH ARE PARALLEL, SECOND BIREFRINGENT MEANS FOR TRANSMITTING INCIDENT ELECTROMAGNETIC WAVE ENERGY OF ORTHOGONAL POLARIZATION THROUGH DIFFERENT SURFACES THEREOF SPACED AWAY FROM SAID FIRST MEANS ALONG THE PATH OF ENERGY TRANSMITTED THEREBETWEEN, SAID SECOND BIREFRINGENT MEANS COMPRISING THIRD AND FOIURTH PRISMS OF GIVEN REFRACTIVE INDEX LESS THAN SAID SEPARATED BY A GAP OF REFRACTIVE INDEX LESS THAN SAID GIVEN INDEX AND WHICH HAVE OPTIC AXIS DIRECTIONS WHICH ARE PARALLEL, ALL EXTERNAL SURFACES OF SAID PRISMS THROUGH WHICH SAID ENERGY PROPAGATES BEING ORIENTED NORMAL TO THE PROPAGATION EIRECTION THERETHROUGH, THE OPTIC AXIS DIRECTION OF SAID FIRST AND SECOND PRISMS AND THE OPTIC AXIS DIRECTION OF SAID THIRD AND FOURTH PRISMIS BEING RELATED BY A 45 DEGREE ANGLE IN AGIVEN ROTATIONAL SENSE, MEANS FOR ILLUMINATING A FIRST SURFACE OF ONE OF SAID PRISMS WITH PLANE POLARIZED ELECTROMAGNETIC WAVE ENERGY HAVING A POLARIZATION PLANE CONTAINING THE OPTIC AXIS OF THE ILLUMINATED MEANS, THE ILLUMINATED SURFACE OF SAID PRISM DEFINING THE FIRST PORT OF SAID CIRCULATOR, MEANS DISPOSED ON SAID PATH FOR ROTATING THE PLANE OF POLARIZATION OF SAID WAVE ENERGY INTO A PLANE WHICH IS RELATED TO THE INPUT POLARIZATION BY 45 DEGREES IN SAID GIVEN ROTATIONAL SENSE, AND LOW LOSS MEANS FOR RECEIVING WAVE ENERGY DISPOSED AT THE REMAINDER OF THE EXTERNAL SURFACES OF SAID PRISMS THROUGH WHICH ENERGY CAN PROPAGATE, SAID REMAINDER OF SURFACES COMPRISING THE REMAINDER OF PORTS OF SAID CIRCULATOR.