动态法拉第效应及其损耗机制

在磁光介质中，法拉第磁光效应的动态特性与静态特性具有明显的差别．交变法拉第旋转θ_t的实部θ′_t恒小于静态法拉第旋转θ_ｓ的实部θ′_ｓ，θ′_t＜θ′_ｓ，而虚部θ″_t＞θ″_ｓ．分析(BiTm)₃(FeGa)₅O₁₂磁光单晶薄膜法拉第效应的测量结果表明，在交流磁场频率ω＞10 关键词：

THE DYNAMIC FARADAY EFFECT AND IT′S-MECHANISM OF LOSSES

There is evidently a difference between the dynamic and static Faraday effects in magnetooptical medium.The real part θ′_t of the alternating Faraday rotation θ_t all is less than the real part θ′_s of the static Faraday rotation θ_s,and the imaginary part θ″_t all is bigger than the imaginary part θ″_s.It is shown by the experimental result of Faraday effect in (BiTm)₃(FeGa)₅O₁₂ films that the frequency dependence of θ_t has a direct bearing on the mechanism of magnetic lag in the high-frequency region of ω>10⁴Hz,and is mainly depend on the magnetic hysteresis in the low-frequency region of ω≤10³Hz.Even if ω→0,θ_t does not equal θ_s as a result of the magnetic hysteresis loss in the medium.It is also indicated by the theoretical analysis that it is impossible to realize completely the on off state of the switch for a modulator utilizing the magnetooptical medium with magnetic losses.