Minovich, AlexanderPowell, David A.Shadrivov, Ilya V.Kivshar, YuriNeshev, Dragomir2015-12-162015-12-160003-6951http://hdl.handle.net/1885/95072We analyze numerically the optical response and effective macroscopic parameters of fishnet metamaterials infiltrated with a nematic liquid crystal. We show that even a small amount of liquid crystal can provide tuning of the structures due to reorientation of the liquid crystal director. This enables switchable optical metamaterials, where the refractive index can be switched from positive to negative by an external field. This tuning is primarily determined by the shift of the cut-off wavelength of the holes, with only a small influence due to the change in plasmon dispersionThis work has been supported by the Australian Research Council and from the National Computing Infrastructure Merit Allocation Scheme.http://www.sherpa.ac.uk/romeo/issn/0003-6951..."Publishers version/PDF may be used on author's personal website, institutional website or institutional repository" from SHERPA/RoMEO site (as at 17/12/15). Copyright 2010 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters and may be found at https://doi.org/10.1063/1.3427429Keywords: Cutoff wavelengths; External fields; Macroscopic parameters; Optical response; Plasmon dispersion; Switchable; Liquid crystals; Liquids; Nematic liquid crystals; Refractive index; Tuning; Metamaterials2010-04-0610.1063/1.34274292016-02-24