BISUBSTITUTED IRON-GARNET FILMS FOR STABLE FARADAY-ROTATION AGAINST WAVELENGTH VARIATION IN THE 1.3 MU-M BAND

We report on the finding of a Bi-substituted Sm-containing iron garnet film (La0.08Sm2.15Bi0.77Fe5O12) that realizes a high Faraday rotation stability against wavelength variation in the 1.3 mu m band. This sta bility resulted from the peaks in the Faraday rotation at 1.24 mu m an d 1.38 mu m due to Sm3+ ions. We calculated that such isolators could provide a 60 nm bandwidth in which the isolation would be maintained a t 35 dB or higher. In addition, we discussed the relationship between the bandwidth and film composition.