LIGHT-MODULATION BY RESONANCE EXCITATIONS OF PERIODIC STRIPE DOMAIN LATTICES IN MAGNETIC GARNET-FILMS

Abstract

Magnetic garnet films of composition (Y, Bi)3(Fe, Al)5O12 are grown by liquid phase epitaxy on [111] oriented substrates of Gd3Ga5O12. They support periodic lattices of parallel stripe domains. A planar slot line antenna is used to excite the domain wall resonance and the two branches of the domain resonance in the frequency range up to 4 GHz. Linearly polarized light passes the crystal perpendicular to the film plane and is diffracted and modulated by the excited domain lattice. The modulation intensity is measured at zero diffraction order as function of frequency and of the static induction applied in the film plane parallel to the stripes. The experimental results are in agreement with calculations on the basis of a hybridization model which takes into account the interaction of all resonances. From the experimental data the precession angles and the wall oscillation amplitudes are derived.