Inverse design of resonant nanostructures for extraordinary optical transmission of periodic metallic slits

This paper has presented inversely determining the resonant configuration of the bilateral nanostructures for periodic metallic slits with extraordinary optical transmission performance. The topology optimization approach is utilized to implement the inverse design procedure. Several geometrical configurations of the bilateral nanostructures are derived for periodic metallic slits. The resonant performance of the derived nanostructures are demonstrated by the transmission spectra, where the transmission peak is presented at the specified wavelength in the inverse design procedure. This provides an approach to control the red or blue shift of the transmission peak or localize the resonant performance at a desired frequency, by specifying the desired incident wavelength in the inverse design procedure. The inverse design method is extended to make the periodic metallic slits to be less sensitive to the incident wavelength. This research can be further extended to inversely find the resonant subwavelength structures for extraordinary optical absorption and other surface palsmon polariton based photonic devices. The inverse design of three dimensional apertures for extraordinary optical transmission will be investigated in our future researches.