It has been more than 20 years since the 1st Nd:Y3Al5O12 (Nd:YAG) polycrystalline ceramic laser was reported, and nowadays, there are a lot of works for transparent ceramics on scintillators, phosphors, faraday rotators, and optical windows not only for laser gain media. A Faraday rotator is one of the key optics element for the isolation and birefringence compensation of laser amplifiers in high-averagepower laser systems and demands high Verdet constant, size scalability, excellent optical quality, high laser damage threshold, and a high thermal conductivity. We report the optical properties, Faraday effect and Verdet constant of ceramic TGG and TAG. Large diameter ceramic TGG (Tb3Ga5O12) have been used as Faraday devices for high-average laser systems. Advanced ceramic TAG (Tb3Al5O12) is a promising Faraday material for high-average-power lasers system.