A perspective on Faraday isolators for advanced lasers

Advances in the development of lasers with high output power raise the problem of increasing the operating power of Faraday isolators, since these devices can be indispensable in a number of applications. Due to the relatively high absorption of laser radiation in magneto-active media that are the basis of isolators, their use in laser systems is limited. In this Perspective, we overview the approaches that can be used to develop Faraday isolators with a high level of operating power and summarize the related achievements made in recent years, which have become possible due to the production of a wide range of new magneto-active media and the study of their properties. The issues and challenges on the path of further progress, as well as promising directions for it, are discussed.