magneto-optic effects in subwavelength nonlinear plasmonic waveguides

We report a new type of magneto-optic effect in nonlinear metamaterial waveguides, composed of an array of split ring resonators (srrs) with varactors. the results show that there exists an ideal wide frequency band for backward-propagating modes, in which a large refractive index change for transverse magnetic (tm) modes can be modulated by an applied low-strength magnetic field, with a low absorption loss simultaneously. in addition, the chirp factor for measuring the validity of refractive modulator is analyzed, and broadly flat chirp spectra are shown. these properties open up an avenue for potential applications of nonlinear metamaterials in nanophotonic devices.