Magneto-optic magnetic-field measuring apparatus for measuring a magnetic field intensity by measuring an angle of diffraction

摘要

A magnetic-field measuring apparatus comprising a polarizing element for generating polarized light that transmits parallel to the lines of magnetic force of a first magnetic field, a Faraday effect element for generating a banded magnetic domain substantially perpendicular to the transmission direction of the polarized light generated by the polarizing element and for diffracting the polarized light by the banded magnetic domain, a magnetic-field generating unit for generating a second magnetic field having lines of magnetic force which cross at right angles with the transmission direction of the polarized light generated by the polarizing element and are parallel to the banded magnetic domain generated by the Faraday effect element, a position detecting unit for detecting a position at which diffracted light of other than zero-order diffracted by the Faraday effect element is received, and a magnetic-field-intensity detecting unit for detecting a magnetic field intensity of the first magnetic field on the basis of the result of detection of the position detecting unit.