Magneto-optical element and optical magnetic field sensor.

摘要

A magneto-optical element is of a rare-earth iron garnet crystal expressed at least by formula 1, and a element in whose composition range the value of X is set at 0.8</=X</=1.3; that of Y at 0.2</=Y</=0.4; that of Z at 0.1</=Z</=0.9; and that of W at 0</=W</=0.3; and R element is made at least one or more kinds of rare-earth elements. An optical magnetic field sensor is composed in such a manner that light diffracted by magnetic domain structure of rare-earth iron garnet crystal can be detected up to a higher-order light by optical fiber on light output side through optical system arrangement. A magnetic field measuring equipment composed of the optical magnetic field sensor has a linearity error of +/-1.0% or less within a magnetic field range 5.0 Oe to 200 Oe, and allows a measuring accuracy higher than with prior art equipment. (BiXGdYRZY3-X-Y-Z) (Fe5-w Gaw) O12 (formula 1) <IMAGE>