Giant Faraday rotation in heavily ce-doped YIG bulk ceramics

Giant magneto-optical properties were achieved by adding Ce to ferrimagnetic YIG (Y3Fe5O12) ceramics. The amount of change in Faraday rotation was 144 deg./cm when 1at.% of Ce was substituted on the Y site of YIG ceramics, and the Faraday rotation of 990 deg/cm was obtained by 8at.% Ce substitution. Doping Ce in iron garnet can give a Faraday rotation function around 5 times higher than that of Bi (29 deg./cm per 1at.% of Bi), which is currently used in optical isolators for telecommunications. The in-line transmittance of 4at.% Ce:YIG ceramics (t = 0.5 mm) at 1550 nm was 62 %, and this ceramic exhibited excellent characteristics as an optical isolator.