YIG and Doped-Derivatives for the Faradays of Future Gravitational-Wave Detectors

LIGO (Laser Interferometer Gravitational-wave Observatory) has allowed us to better understand the universe in ways we were not able to before. While detecting black-hole mergers and neutron star collisions, future upgrades aim to increase the sensitivity of the LIGO detectors even further, in an effort to look deeper into the cosmos, close to the origins of our universe. Among the upgrades, changing the wavelength of the laser and cryogenic operation are considered. Faraday isolators are devices that protect the detectors from stray light and are strongly affected by the operating wavelength and the temperature. These isolators need to be redesigned for future gravitational wave detectors, and new materials for their use, need to be investigated. In this presentation I will discuss the performance of Yttrium Iron Garnet (YIG) and doped-derivatives, and their suitability for next generation gravitational-wave detectors, as well as the effect of the temperature on their performance.