High efficiency two-dimensional grating reflectors with angularly tunable polarization efficiency

We report on two-dimensional high-contrast subwavelength gratings with a polarization efficiency that is tunable in the angular spectrum. Due to the high index contrast it is possible to realize highly efficient reflectors with nearly angular independent reflection for light with transverse-electric polarization. Simultaneously, for transverse-magnetic polarized light the minimum and maximum reflectance can be tuned to a defined angle of incidence. Configurations with minimized and maximized polarization efficiencies at incidence angles of 0° and 45° are exemplified for a design wavelength of 1550 nm. For the case of minimum polarization efficiency we present the experimental results for a non-monolithic and a monolithic realization.