Pawlowski, E.E.PawlowskiEngel, H.H.EngelFerstl, M.M.FerstlFurst, W.W.FurstKuhlow, B.B.Kuhlow2022-03-032022-03-031994https://publica.fraunhofer.de/handle/publica/18551910.1117/12.153180Two-dimensional arrays of Fresnel zone microlenses were fabricated and coated with antireflection layers by an ion beam sputter deposition technique. The reflection of these lenses was analyzed on the basis of an angular spectrum approach for different substrate materials. A minimum reflectivity as low as 2*10-4 was realized by means of in situ controlled multilayers of TiO2 and SiO2. The lenses have a circular aperture of 2 mm and different focal lengths for the wavelengths of 1.52 and 0.63 mu m, respectively. The kinoform profile in each zone of the Fresnel zone lenses was approximated by an eight-level profile. Such stepped profiles were realized with several masks written with an electron beam and transferred by photolithographic technology. The measurements reveal that the spot sizes of the fabricated microlenses are close to the diffraction-limited values.enantireflection coatingscomputer-generated holographyelectron beam lithographyholographic optical elementslensesmasksoptical workshop techniquesphotolithographyreflectivitysputter depositioncomputer-generated hologramsdiffractive microlenses2d arrayselectron beam writingthin film depositionfresnel zone microlensesion beam sputter depositionangular spectrum approachminimum reflectivityin situ controlled multilayerskinoform profileeight-level profilestepped profilesphotolithographic technologydiffraction-limited values1.52 micron0.63 microntio2-sio2 multilayers621535journal article