  An oblique helicoidal state of a cholesteric liquid crystal (ChOH) is capable
of continuous change of the pitch P in response to an applied electric field.
Such a structure reflects 50% of the unpolarized light incident along the ChOH
axis in the electrically tunable band determined by P/2. Here we demonstrate
that at an oblique incidence of light, ChOH reflects 100% of light of any
polarization. This singlet band of total reflection is associated with the full
pitch P. We also describe the satellite P/2, P/3, and P/4 bands. The P/2 and
P/4 bands are triplets while P/3 band is a singlet caused by multiple
scatterings at P and P/2. A single ChOH cell acted upon by an electric field
tunes all these bands in a very broad spectral range, from ultraviolet to
infrared and beyond, thus representing a structural color device with enormous
potential for optical and photonic applications.
