title: Highly tunable optical activity in planar achiral terahertz metamaterials.
abstract: Using terahertz time domain spectroscopy we demonstrate tunable polarization rotation and circular dichroism in intrinsically non-chiral planar terahertz metamaterials without twofold rotational symmetry. The observed effect is due to extrinsic chirality arising from the mutual orientation of the metamaterial plane and the propagation direction of the incident terahertz wave.
authors.affiliation: School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, Oklahoma 74078, USA. ranjan@lanl.gov
authors.forename: Ranjan
authors.initials: R
authors.lastname: Singh
authors.forename: Eric
authors.initials: E
authors.lastname: Plum
authors.forename: Weili
authors.initials: W
authors.lastname: Zhang
authors.forename: Nikolay I
authors.initials: NI
authors.lastname: Zheludev
mesh_terms: D001718:Birefringence; D002942:Circular Dichroism / Q000295:instrumentation / Q000379:methods*; D004574:Electromagnetic Fields; D008027:Light; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods; D008962:Models, Theoretical; D055095:Optics and Photonics / Q000295:instrumentation / Q000379:methods*; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*