Hannam, KirstyPowell, David A.Shadrivov, Ilya V.Kivshar, Yuri2015-09-242015-09-240003-6951http://hdl.handle.net/1885/15684We introduce a chiral metamaterial with strong, non-resonant optical activity, and very low polarization ellipticity. We achieve this by combining a meta-atom and its complementary structure into a meta-molecule, resulting in the coupling of magnetic and electric dipole responses. In contrast to either a pair of crosses, or complementary crosses, this structure has low dispersion in the optical activity at the transmission resonance. We also study the excitation mechanism in this structure, and optimize the optical activity through changing the twist angle.4 pageshttp://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 24/09/15). Copyright 2013 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 (Hannam, Kirsty, et al. "Dispersionless optical activity in metamaterials." Applied Physics Letters 102.20 (2013): 201121.) and may be found at https://doi.org/10.1063/1.4807438Keywords: Chiral metamaterial; Dispersionless; Electric dipole; Excitation mechanisms; Low dispersions; Optical activity; Transmission resonance; Twist angles; Metamaterials; Optical materials2013-05-2410.1063/1.48074382016-02-24