Analysis of Interaction between Optical Waves and Magnetostatic Surface Waves in Three-Dimensional Optical Waveguide Using Multilayered Garnet Structure

Optical-MSSW interaction has received wide interest for realization of thin film devices for optical signal processing at microwave signal frequency. In this paper, a device structure to obtain optical-MSSW interaction in a threedimensional optical waveguide using a multilayered garnet structure is proposed and analyzed. The multilayered structure enables optimization of the waveguide parameters, separately, for optical and MSSW propagation. Interaction in a threedimensional optical waveguide is promising for integration of the device with other optical integrated circuits. Optical and MSSW propagation characteristics in the multilayered device are investigated and the optical mode conversion characteristics between the Ez pq and the E x pq modes supported by the three-dimensional optical waveguide are derived. The dependence of the mode coupling coefficient on the waveguide parameters, such as the film thicknesses, waveguide width, saturation magnetization, and the MSSW power is also analyzed. It is demonstrated through a numerical example that, by proper selection of the waveguide parameters, it is possible to achieve practical device dimensions. key words: MSSW, microstrip, waveguide, garnet, mode cou-