Application of magneto-optics

The interaction between an optical wave and a magnetic medium leads to a wide variety of effects, as described in the article [E1960] on magneto-optical effects and materials. Magneto-optical Faraday and Kerr effects are widely used for highly sensitive vector measurements of magnetization and microscopic observations of magnetism. Thanks to their exceptional spatial and temporal resolution, they enable dynamic imaging of magnetic domains. Today, these techniques are widely used to test devices, particularly in the field of spin electronics.

The applications of magneto-optics cover many fields: optical telecommunications, information storage, memories, visualization and sensors. The use of miniaturized non-reciprocal devices, such as isolators or circulators, makes it possible, by analogy with guided microwave systems [E 3330][E 3331][E 3336] , to fulfill new functions based on optical links.

The design and miniaturization of the proposed devices have evolved rapidly thanks to advances in laser and computer technology. They have also benefited from the emergence and mastery of new artificial materials such as ultra-thin film structures, magnetic nanostructures and magneto-photonic crystals. Magneto-optics is also of interest to the non-destructive testing sector, and is proving to be a very powerful investigation tool in solid state physics.

For data storage, after intensive research into optically addressable and rewritable memories, the magneto-optical disk has established itself in several peri-computer and consumer audio niches.

Faraday rotation in ferrimagnetic garnets has also been...