Spectral holes in Bragg reflection from chiral sculptured thin films: circular polarization filters

Chiral sculptured thin films (STFs) display the circular Bragg phenomenon, whereby their planewave transmittance spectrums exhibit narrow-bandstop characteristics in several wavelength regimes. The insertion of a homogeneous, anisotropic, thin layer between two layers of the same chiral STF is shown to result in the exhibition of ultranarrow-bandpass characteristics which can be tuned by rotating the three-layer structure. (C) 2000 Elsevier Science B.V. All rights reserved.