Patent ID: 7271900

Claim:
A magneto-optical imaging method comprising: generating a polarized incident light beam by a light source, positioning, close to a tax get material, a substantially plane face of a magnetic active material suitable for producing a Faraday rotation in the polarized light beam, generating an exciting magnetic field of angular frequency ω in the target material, directing the polarized incident light beam, through the active material, toward the target material, observing the angle of Faraday rotation in the reflected beam, with respect to the incident beam, which is created in the active material by an interfering magnetic field produced by the target material, wherein said method also comprises: modulating the luminous intensity of the polarized light by the light source stroboscopy, lock-in detecting by photodetector means, a reflected beam corresponding to the reflection on a reflecting surface being located between the active material and the target material, and determining the amplitude and the phase of the interfering magnetic field, from the detected luminous intensity of the reflected beam, function of the observed angle of Faraday rotation, the Faraday rotation of the active material being substantially proportional to its magnetization when it is subjected to an interfering magnetic field, perpendicular to said face and varying in a minimum range extending between substantially −100 Oersted and substantially +100 Oersted.