Interaction of optical waveguide modes with magnetostatic surface waves in tangentially magnetized finite samples

To increase the efficiency of the diffraction of optical waveguide modes by magnetostatic waves (MSW) and thus to improve the performance of the magnetooptical devices based on this principle one has to confine both waves in a limited sample of a ferrimagnetic film. This paper reports the results of the experimental investigation of the peculiarities of the collinear interaction of guided light with surface MSW in a three-dimensional YIG-GGG waveguide. While measuring the frequency response of the interaction we scanned the light beam across the film. This made it possible to identify the optical response of different transverse modes of surface MSW ( n=1, 2, 3, 4) and of volume MSW ( n=6). To excite different numbers of transverse modes including antisymmetric ones we changed the orientation of the transmitting antenna with respect to the direction of the bias magnetic field.