Effects of the Induced Uniaxial Anisotropy on Bragg Diffraction of Guided Optical Wave by Magnetostatic Backward Volume Wave

This paper presents a theoretical investigation of the effects of the induced uniaxial magnetic anisotropy on Bragg diffraction and mode conversion of a guided optical wave (GOW) by a magnetostatic backward volume wave (MSBVW). The cases of both the easy axis normal and parallel to the film have been considered. The numerical results for a Bi-doped yttrium–iron–garnet–gadolinium–gallium–garnet (YIG–GGG) waveguide show that the induced uniaxial anisotropy has significant effects on the mode conversion efficiency of GOW and magneto-optic coupling bandwidth. In particular, the induced uniaxial perpendicular anisotropy can enhance the mode conversion efficiency and magneto-optical bandwidth. Thus, the performances of MSBVW-based magneto-optical waveguides can be improved by using a magnetic film that possesses the induced uniaxial perpendicular anisotropy.