Guided and leaky modes in magneto-optical sandwiches with ultrathin metal films

Abstract Using coordinate-free effective medium formalism, we derive the waveguiding conditions and examine the modal structure for trilayer magneto-optical sandwiches composed of ultrathin absorbing magnetized film bounded between two dielectric layers. We focus on the influence of absorption in metal film and applied DC magnetic field on the modal dispersion curves and polarization states of the eigenwaves. Arguing with Pistora's group (Pistora et al., J. Magn. Magn. Mater. 157/158 (1996) 283; J. Magn. Magn. Mater. 198/199 (1999) 683), we state that it is the form birefringence of the multilayer system that can lead to a practically important effect—perfect phase matching of guided optical waves at certain frequencies and for certain propagation constants.