The Problems in the Development of Magneto-Optical Devices

The problems to be solved in the development of future magneto-optical devices are described. Iron garnets, especially bismuth substituted iron garnets, are promising for magneto-optical materials in the 0.8 μm and 1.l-1.6 μm wavelength ranges. However, further improvement of the figure of merit and crystal growth technique is fundamental to realizing high-quality, compact and low-cost devices. With the advance of visible laser diodes, a new class of magneto-optical materials such as CdMnTe will be required for the shorter wavelength region. For waveguide devices, it seems important to develop various basic technologies, such as TE-TM mode phase matching, control of ofmagnetization direction, and fabrication of nonreciprocal and reciprocal pats in a film. Lastly, the problems in thin film integrated optical devices based on Bragg diffraction of guided light by magnetostatic surface waves are briefly described.