Doped yttrium iron garnet (YIG) thin films for integrated magneto-optical applications

A novel single-source MOCVD technique was used to deposit Ce:YIG ((Ce,Y)(3)Fe5O12) films which were investigated for integrated magneto-optical applications, such as waveguide isolators. These films were grown on gadolinium gallium garnet substrates in order to optimize the growth conditions before growth on semiconductor substrates was attempted. We were able to achieve very high ratios of Ce:Y (= 0.4) due to the nonequilibrium nature of MOCVD. Ce:YIG films on GGG substrates were epitaxial with excellent optical and magnetic properties, along with high Faraday rotations that were comparable to commercial Bi:YIG. Planar waveguiding was observed in Ce:YIG films on both GGG and MgO substrates. MgO also proved to be a successful buffer layer for protecting the semiconductor substrates during YIG deposition. The Ce:YIG films on MgO-buffered GaAs had very promising magnetic properties, but the MgO deposition on InP must be optimized before successful Ce:YIG films on InP can be achieved.