Faraday rotation spectra of bismuth-substituted rare-earth iron garnet crystals in optical communication band

Bismuth-substituted rare-earth iron garnet (REBIG) crystals are used in optical isolators for optical communication. However, the Faraday rotation (FR) spectra of REBIG crystals in the wavelength region of 1.3-1.6 mum have not yet been theoretically studied. To interpret the spectra, we assumed that the FR in this wavelength range was dominated by the contribution of the electric dipole transitions, and calculated the FR spectra. REBIG bulk crystals were grown from the Bi2O3 self-fluxed melt by the top-seeded solution growth method. The experimental results agreed with the theoretical calculation of FR in (HoBi)(3)Fe5O12, (YbBi)(3)Fe5O12, (YYbBi)(3)Fe5O12, and (TbBi)(3)Fe5O12. The results indicate that the theoretical analysis method of the FR spectra of REBIG in the visible range of wavelengths can be applied in the optical communication band. (C) 2004 American Institute of Physics.