Freese, W.W.FreeseKämpfe, T.T.KämpfeKley, E.-B.E.-B.KleyTünnermann, A.A.Tünnermann2022-03-112022-03-112010https://publica.fraunhofer.de/handle/publica/36673110.1117/12.8435262-s2.0-77951616315Subwavelength structures open up the possibility to create an artificial index material which enables the realization of high-efficient diffractive structures. This can be used to generate optical elements with nearly arbitrary phase profiles. We demonstrate the realization of computer-generated holograms based on this effective medium approach. High diffraction efficiencies can be realized by multi-phase-level modulation based on two-dimensional binary nanostructures. The fabrication is performed by one lithographical step using a high-speed e-beam writer which allows high-resolution patterning even on large areas. A diffractive element in the visible range is experimentally demonstrated using the presented effective index approach.enbinary subwavelength structuresmultilevel computer-generated hologramsdiffractive optics620conference paper