DyBi Garnet Films with Improved Temperature Dependence of Faraday Rotation

The effects of host rare-earth ions (Dy, Gd, Yb) on Bi-substituted garnet film Faraday rotation coefficient (¿F) variation with temperature were investigated in an effort to improve the isolation of such media used in optical isolators. Even when semiconductor laser wavelength fluctuations (1.310 ± 0.0025 ¿m) due to environmental temperature change were taken into consideration, observations and calculations showed that in the temperature range 0 to 50°C, the theoretical isolation value for Dy2.5Bi0.5Fe5O12 can exceed 29 dB. The authors determined that (DyBi)3Fe5O12 epitaxial film Faraday rotation coefficient (¿900 deg/cm, 1.3 ¿m) has low temperature variation when used as isolator material.