  Theory shows that a slab of a dielectric structurally chiral material (DSCM)
exhibits both linear and circular dichroisms because of its anisotropy and
structural chirality, for normal as well as oblique incidence. This conclusion
was confirmed by fabricating a chiral sculptured thin film and measuring the
spectra of its reflectances and transmittances, both linear and circular.
Signatures of the circular Bragg phenomenon are evident in the spectra of all
reflectances, transmittances, absorptances, and dichroisms. Reversal of the
structural handedness of a DSCM and rotation of the projection of the direction
of propagation of the incident light clockwise instead of counterclockwise
about the axis of helicoidal nonhomogeneity simultaneously changes the sign of
circular dichroism but has no effect on linear dichroism.
