Enhanced Tunable Bragg Diffraction in Large-Pore Inverse Opals Using Dual-Frequency Liquid Crystal

Elton Graugnard, Boise State University
S. N. Dunham, Georgia Institute of Technology
J. S. King, Georgia Institute of Technology
D. Lorang, Georgia Institute of Technology
S. Jain, Georgia Institute of Technology
C. J. Summers, Georgia Institute of Technology

Abstract

Large-pore TiO2 inverse opals were fabricated by atomic layer deposition in sintered polystyrene colloidal crystal templates and infiltrated with dual-frequency liquid crystal. The optical properties of the hybrid organic/inorganic structure were characterized by reflectance measurements of the Bragg peak, the position of which was tuned using a frequency dependent applied electric field. A 6 nm blueshift was observed for frequencies less than 13 kHz and a 13 nm redshift for frequencies above 13 kHz. These results demonstrate enhanced optical tunability in three-dimensional photonic crystals and are important for the development of active photonic devices.