Ca添加Bi置換鉄ガーネット膜の光吸収損失に及ぼす還元効果

抄録

Reducing treatment effects on magneto-optical properties were studied for Ca-doped Bisubstituted iron garnet (BiGdCa)₃(FeAlGa)₅O₁₂ films grown by the LPE technique. The films were reduced by using a hydrazine solution at 100∼110°C. Faraday rotation and absorption loss of as-grown and reduced films were measured at wavelength λ between 0.5 and 2.0 μm. By reducing treatment, the Faraday rotation remained unchanged, however, the absorption loss decreased for both Ca-free and Ca-doped films. The reduced Ca-doped films had lower absorption loss compared with that of the reduced Ca-free films. The minimum absorption loss reached 220 dB/cm at λ=0.79 μm and 1∼2 dB/cm at λ=1.15 μm. The saturation field was below 200 Oe for all the films.
An optical isolator for the 0.8 μm region was constructed by using a reduced thick film. The forward loss of the isolator was 3 dB and the backward loss 27 dB at 0.79 μm.