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 (θ
_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 μm) 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 Dy
_2.5
Bi
_0.5
Fe
₅
O
₁₂
can exceed 29 dB. The authors determined that (DyBi)
₃
Fe
₅
O
₁₂
epitaxial film Faraday rotation coefficient (-900 deg/cm, 1.3 μm) has low temperature variation when used as isolator material.