Near-Infrared Polarization-Manipulated Anisotropic Transmission Through Metallic Array of Subwavelength Fractal Slits

Transmission through subwavelength fractal slits on Ag film in near-infrared (from 1 μm to 1.4 μm ) region has been achieved. It is proved by both simulation and experiment that polarization-manipulated anisotropic transmission and oblique incidence invariance exist. It is also demonstrated that the film depth constitutes an important factor for local resonances. Spectra of modified slits' length and pattern are investigated, and are compared with that of periodic rectangular and square hole array. It is confirmed that anisotropic transmission and angle invariance transmission come from the largest rectangular slits whose long borders are normal to incidence polarization. These results pose applications for peak-concentrated polarization-controlled optical device.