▎ 摘　　要

Optical responses of planar composites made of monolayer graphene sheets and axially helicoiclal (bi) anisotropic films (HBFs) are studied using our developed algorithm based on spectral-domain exponential matrix (SDEM) technique. Such HBF-based structures possessing z-axis inhomogeneity, in particular, include locally uniaxial chiral nematic and biaxially smectic liquid crystals (CNLC and CSLC) with double or a few layered graphene sheets inserted. In our mathematical treatment, they are artificially divided into many very thin sub-layers, where each one can be described by a set of z-coordinate independent constitutive tensors. The effects of wavelength and angle of the incident light, chemical potential of monolayer graphene, period of the z-axis inhomogeneity and angle of rise of the composites on their reflectance and transmittance are investigated numerically for different constitutive features and geometries. It is shown that the first- and second-order Bragg reflection or transmission zones at optical bands do exist in the presence of double or a few layered dispersive graphene sheets with slight loss but more freedom introduced. (C) 2013 Elsevier B.V. All rights reserved.