Optical transmission resonances tuned by external static magnetic field in an n-doped semiconductor grating with subwavelength slits

Transmission behavior of light through a grating consisting of n-doped semiconductor with subwavelength slits under the application of external static magnetic fields is investigated. As dielectric constant of n-doped semiconductor can be substantially altered by applied magnetic field, in the Voigt configuration and for TM-polarized illumination, two transmission resonance peaks associated with localized waveguide modes of slits are significantly shifted toward the lower frequency regime with the increase of the applied magnetic field. These characteristics can be assigned to a reduction of effective plasma frequency of n-doped semiconductor under the applied magnetic field. Our findings may provide possibility for achieving tunable transmission resonance spectrum.