title: Polarization-universal bandgap in periodically twisted nematics.
abstract: Cholesteric liquid crystals are known to possess bandgap and exhibit strong reflection for one of two circular polarizations of light. We suggest a periodically twisted nematic liquid crystal as a medium, which possesses bandgap and exhibits strong reflection for any polarization of normally incident light. Two possible structures are considered: a sinusoidal modulation profile and a rectangular modulation profile. In both cases, the maximum bandgap of a periodically twisted structure is approximately twice as narrow as that of cholesterics. However, the polarization properties of these structures may make them more advantageous than cholesterics in a variety of applications.
authors: College of Opitcs and Photonics/CREOL, University of Central Florida, Florida 32816-2700, USA. hakob@creol.ucf.edu
authors: Hakob
authors: H
authors: Sarkissian
authors: Boris Ya
authors: BY
authors: Zeldovich
authors: Nelson V
authors: NV
authors: Tabiryan