Accurate magneto-optic sensitivity measurements of some diamagnetic glasses and ferrimagnetic bulk crystals using small applied AC magnetic fields

Many materials exhibit a relatively large Faraday effect. A plane polarized optical beam passing through these materials has its plane of polarization rotated by a measurable amount proportional to the applied magnetic field strength parallel to the propagation direction of the beam. Some of the most sensitive materials of this kind are diamagnetic glasses and ferrimagnetic crystals. We have made accurate measurements of the magneto-optic sensitivity of a variety of diamagnetic glasses and ferrimagnetic bulk optic crystals using small applied ac magnetic fields in contrast to the more common technique involving very strong applied dc magnetic fields