Diffusive reflections in chiral photonic crystals on nanoimprinted CYTOP films

Cholesteric liquid crystals (CLCs) with periodical helical structures of nematic molecules are chiral photonic crystals that exhibit photonic band gaps for circularly polarized lights with same handedness as CLC helices. We investigated optical characteristics of CLCs on nanoimprinted CYTOP films. Here, nanoimprinted CYTOP films are used as alignment layers to control orientations of cholesteric helices because of its strongly hydrophobic surface with low polarity and low polarizability. The CLCs on the nanoimprinted films showed not specular but diffusive reflections at the specific spectral region. This nanostructured CYTOP film can provide new possibility to engineer optical characteristics of the CLCs.