Patent ID: 7206116
Filing Date: 2007-04-17
Classification: G02F,H01F

Abstract:
1. A Faraday rotator for a Faraday isolator, the Faraday rotator comprising a roller-shaped magnetooptical crystal having an axis of symmetry, a right circular hollow cylinder comprised of a permanent magnetic material surrounding the crystal, the cylinder being axially magnetized whereby a magnetic field thereof approximately parallel to the axis of symmetry extends into the hollow of the cylinder, the magnetic field running in only one direction from a north pole to a south pole, and respective right cylindrical permanent magnets attached to respective end faces of the hollow cylinder-surrounded crystal, each of said end face magnets having an aperture therethrough which is coaxial with the axis of symmetry, wherein at least a region of one of the end face magnets at the north-magnetized end of the axially magnetized cylinder is radially magnetized from interior to exterior whereby a magnetic field of said one end face magnet has its north pole radially inward and its south pole radially outward and at least a region of the other end face magnet at the south-magnetized end of the axially magnetized cylinder is radially magnetized from exterior to interior whereby a magnetic field of said other end face magnet has its south pole radially inward and its north pole radially outward.