Novel optical cross polarization converters based on slotted nanoantennas

The capability to manipulate the polarization state of electromagnetic waves and light is important in optical systems. Metamaterial (MM) as an alternative to manipulate the wave polarization state have drawn considerable attention due to its attractive characteristics, such as near zero refractive index, cloaking, etc. Thus a number of electromagnetic wave polarizer and wave plate have been realized through anisotropic and chiral MMs. Researchers have discovered that the strong polarization dependence is highly related to the localized surface plasmon excitations induced by the nanoscale composite element in these MMs. Correspondingly, it is found that the resulting polarization converters based on MMs suffer from narrow operating bandwidth. Therefore, it is highly desirable to design broadband and multiple-band polarization converters that can realize different polarization conversions.