Abstract: The present invention relates to an optical insulator for high power optical radiation. The arrangement of the optical insulator comprises a Faraday rotator, comprising one or more Faraday media (4) and a magnet assembly (1) that allows for the receiving of multiple Faraday media (4). A polarizer assembly is arranged both in front of and behind the Faraday media (4). The magnet assembly (1) is formed by magnets (2) shaped in such a way that at least the outer-lying magnets are parallelepiped. The free aperture (3) is surrounded by three magnetic levels (12, 12?, 12?).