We propose to induce a two-dimensional (2D) periodic modulation structure into a planar Grandjean cholesteric liquid crystal (CLC) to demonstrate the intrinsic 2D photonic crystal properties of such materials. The structure combines a thin transmission grating and a Bragg reflective grating. One advantage of using CLC is the intrinsic high quality Bragg structure, which can be modulated by an electric field: shifting the wavelength band edge by changing the applied field. Another interesting property is the polarization dependence. The main difference between using CLC Bragg instead of a linear grating is the need to operate with a circularly polarized light, because the CLC modes are circular in such a regime. We present preliminary results obtained with what we believe to be the first switchable photonic CLC (PCLC) sample, made up of a polymer CLC gel.
© 2007 Optical Society of America
Diffraction and Gratings
Original Manuscript: March 16, 2007
Revised Manuscript: June 27, 2007
Manuscript Accepted: July 6, 2007
Published: September 11, 2007
Alexey Denisov and Jean-Louis de Bougrenet de la Tocnaye, "Resonant gratings in planar Grandjean cholesteric composite liquid crystals," Appl. Opt. 46, 6680-6687 (2007)