REFLECTION AND REFRACTION OF SPIN-WAVES IN UNIAXIAL MAGNETS IN THE GEOMETRICAL-OPTICS APPROXIMATION

The laws governing the propagation of magnetization waves are investig ated in the geometrical-optics approximation, in which a spin wave can be treated as a ray. The refractive index for a spin wave on the inte rface between two magnets with different exchange coupling constants a nd magnetic anisotropy constants is determined. The dependences of the intensity of the reflected wave and the refractive index on the spin- wave frequency and the strength of the external uniform magnetic held are calculated. Estimates of the dimensions of inhomogeneous inclusion s that perform functions analogous to the functions of lenses and mirr ors in optics are presented. The possibility of using the same inhomog eneities both as lenses and as mirrors, depending on the magnetic fiel d strength, is pointed out. (C) 1998 American Institute of Physics. [S 1063-7842(98)01102-7].