Kerr effect

The Kerr effect is a phenomenon used in the readout of magneto-optical memories.

In the Kerr effect, suitable substances reflect polarized laser light depending on their magnetized surface, rotate it in the polarization axis and change its ellipticity.

Both effects result from birefringence, i.e. in the Kerr effect there are two different refractive indices. The direction of rotation of the light is determined by the magnetic field, the deviation from the original position is the Kerr angle. It is between 0.5 ° and 8 ° for the materials used in magneto-optical memories. The Kerr effect is named after its discoverer Rev. John Kerr, M.A., (1824 - 1907).