BISUBSTITUTED IRON-GARNET FILMS EXHIBITING STABLE FARADAY-ROTATION AGAINST WAVELENGTH VARIATION IN THE 1.55 MU-M BAND

We found a Bi-substituted iron garnet film (Tb1.86Bi1.14Fe4.67Al0.24Co 0.09O12) which was characterized by stable Faraday rotation against wa velength variation in the 1.55 mu m band. First, Co-and-Bi-substituted iron garnet films were grown by the liquid phase epitaxy (LPE), and t he dependence of their Faraday rotation against wavelength variation w as measured. It was found that the dependence of Bi-substituted iron g arnet films on wavelength was reduced in the 1.55 mu m band due to a F araday rotation attributable to Co3+ ions. Faraday rotation-wavelength coefficients (FWC) of these films in the 1.53 mu m - 1.57 mu m band w ere 0.01%/nm, or virtually zero. Also relations between FWC and film c omposition were discussed.