Magnetooptical Faraday effect amplified by surface waves in 1D systems

Method of coupled modes is applied to study multilayer schemes, enhancing the magnetooptical Faraday effect with plasmon and other surface resonances. It is shown that the enhancement is achieved due to generation and amplification of a mode that is cross polarized to incident ones. The generation is due to coupling in MO layer. Thus, the overlap of modes is essential. In a scheme with surface plasmon resonance only wave of cross polarization is amplified. The overlap is weak for this scheme, and the amplitude of excited cross polarization mode is small too: it is determined by logarithm of the resonator Q factor. The result can be improved by revision of scheme, which makes the overlap larger. Then the cross-polarization intensity is linear in Q factor. In the latter case the cross-polarization intensity is linear in Q factor. A standard scheme with defect-mode leads to quadratic Q dependence.