Light propagation analysis and high‐speed electro‐optic switching in one‐dimensional photonic crystal with nematic liquid crystal defect layer

Abstract

AbstractIt is possible by the application of voltage to control the local level in a one‐dimensional photonic crystal with a liquid crystal defect layer. In the present paper, a nematic liquid crystal is used and high‐speed switching is attempted on the basis of the shift of the localized state wavelength by the photonic bandgap and liquid crystal orientation control. First, by the finite‐difference time‐domain method, the optical propagation characteristics inside a one‐dimensional photonic crystal with a liquid crystal defect layer are analyzed. It is shown that optical switching by control of the localized state wavelength is possible. TiO2 and SiO2 are periodically laminated as a one‐dimensional photonic crystal. A nematic liquid crystal layer is introduced as a defect layer to disturb the periodicity, resulting in a one‐dimensional photonic crystal with a liquid crystal defect layer. By application of a voltage, the orientation of the liquid crystal defect layer is varied in an attempt to perform optical switching by electric field control of the localized state. High‐speed optical switching of microsecond order is successful with nematic liquid crystals. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 88(4): 46–53, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20087