Faraday Effect Devices, Optical Isolators

Although discovered over 150 years ago, it was not until the 1970's that materials were developed that enabled magneto-optic (Faraday) effect devices of practical sizes. These developments are: magneto-optic materials with high Verdet constants, and the rare-earth magnet materials, capable of extremely high magnetic fields.The magneto-optic effect has enabled development of equipment used in diverse laser applications, from industrial use to fiber-optic telecommunications.The principle of operation of optical isolators and circulators is described herein, as well as descriptions of critical components in such equipment, such as the polarizers and the magnets.