We claim:
1. A magneto-optic magnetic field sensor comprising:
a high-permeability magnetic flux concentrator;
a high-permeability magneto-optic material located in physical contact with said magnetic concentrator and providing a continuous path of high-permeability between the magneto-optic material and the magnetic flux concentrator;
said magnetic concentrator further comprising a cross-sectional area substantially greater than the cross-sectional area of said magneto-optic material;
an optical detector;
a sensing beam of light; and
said magnetic flux concentrator further including a channel therethrough allowing the sensing beam of light to transmit through the channel and simultaneously through the magneto-optic material, and then to the optical detector.
2. The magnetic field sensor of claim 1 wherein said magnetic flux concentrator further comprises a pair of cylindrical members located co-axially one on each end of said magneto-optic material and co-axial to the longitudinal axis of the magneto-optic material.
3. The magnetic field sensor of claim 2 wherein said pair of cylindrical members further comprise a tapered end adjacent said magneto-optic material.
4. The magnetic field sensor of claim 2 wherein said pair of cylindrical members is selected from the group consisting of nickel-zinc ferrite and magnesium-zinc ferrite compositions.
5. The magnetic field sensor of claim 2 wherein said magneto-optic material further comprises a cylindrical shape with the ends of the cylinder partially inserted into said respective channels in said pair of cylindrical members, thereby leaving a gap between said pair of cylindrical members.
6. The magnetic field sensor of claim 1 wherein said magneto-optic material further comprises a ferromagnetic iron garnet crystal.
7. The magnetic field sensor of claim 1 wherein said optical sensing beam further comprises a plane polarized beam formed by the use of a laser beam in conjunction with a collimating lens and a polarizer.
8. A magneto-optic magnetic field sensor comprising:
a high permeability magneto-optic sensor having a longitudinal axis;
a pair of cylindrical high-permeability magnetic flux concentrators aligned on each end of said magneto-optic sensor and in co-axial alignment with said magneto-optic sensor;
said pair of flux concentrators each further comprising a hole along its longitudinal axis and a cross-sectional area substantially greater than said magneto-optic sensor;
said magneto-optic sensor further comprising partial insertion into each of said flux concentrator holes leaving a gap between said flux concentrators;
a linearly-polarized sensing beam passing through one of said flux concentrator holes then said magneto-optic sensor then the other of said flux concentrator holes; and
a detector sensing changes in the sensing beam intensity caused by changes in the Faraday rotation of the sensing beam as the sensing beam passes through the magneto-optic sensor and a polarizer.