Tunable face-centered-cubic photonic crystal formed in holographic polymer dispersed liquid crystals

Abstract

We report on the fabrication and electro-optic measurements of face-centered-cubic (fcc) lattices in holographic polymer dispersed liquid-crystal materials. Four linearly polarized coherent plane waves were interfered to generate a fcc optical lattice that was subsequently and indefinitely recorded as an arrayed pattern of nanometer-sized liquid-crystal droplets $\left(\sim 50 \mathrm{nm}\right)$ at lattice nodes within a polymer matrix. Observed transmission spectra and Kossel diffraction curves are consistent with fcc crystal structure. A completely reversible 2% wavelength shift of the $\left(\pm \mathrm{1 1 1}\right)$ stop band was observed on application of an electric field.