Helgert, C.C.HelgertMenzel, C.C.MenzelRockstuhl, C.C.RockstuhlPshenay-Severin, E.E.Pshenay-SeverinKley, E.-B.E.-B.KleyChipouline, A.A.ChipoulineTünnermann, A.A.TünnermannLederer, F.F.LedererPertsch, T.T.Pertsch2022-03-042022-03-042009https://publica.fraunhofer.de/handle/publica/21861210.1364/OL.34.000704We present and evaluate theoretically and experimentally a design for a negative-index metamaterial that is termed the "Swiss cross" structure. Compared with the established fishnet structure, the proposed design eliminates the drawback of polarization-dependent effective optical parameters. The new design is fabricated by means of e-beam technology and experimentally analyzed using spectroscopic techniques. The thorough comparison with numerical simulations reveals an effective refractive index of n=-1.9 at an operational wavelength of 1400 nm that is independent of the incident polarization. The resonances of the system are comprehensively discussed. (C) 2009 Optical Society of Americaenphotonic metamaterialoptical frequencyrefractive index620535journal article