Patent ID: 7821259

Claim:
Device for the examination of magnetic properties of objects having a magneto-optical layer having magnetic domains, wherein the optical properties of the magneto-optical layer are influenceable by the magnetic properties of the object to be examined, comprising: at least one light source arranged to generate light incident upon the magneto-optical layer; a polarizer arranged to polarize the light generated by the light source; and at least one sensor arranged to receive either of or both light transmitted and light reflected by the magneto-optical layer, wherein the device is provided with a magnet device generating a first magnetic field which is substantially parallel to the surface of the magneto-optical layer and which flows through the magneto-optical layer, wherein the magnetic properties of the object to be examined generates a second magnetic field, and wherein the second magnetic field is perpendicular to the surface of the magneto-optical layer and rotates the polarization direction of the light in the magneto-optical layer.