A transflective optical film reflects ambient light incident on the first surface
and transmits light having a preferred polarization state incident on the opposite
surface. The film has a substrate wherein a plurality of tapered cavities extends
from a first surface of the substrate toward an opposite surface, the tapered cavities
narrowing toward the opposite surface, and a filler material deposited within each
the tapered cavity. A reflective layer is deposited on the filler material in each
tapered cavity, along the first surface of the substrate. At least one of the substrate
and the filler material is birefringent such that for a preferred polarization
state, the refractive index of the filler is substantially lower than the refractive
index of the substrate and that, for the polarization state orthogonal to the preferred
polarization state, the refractive index of the filler is substantially the same
as the refractive index of the substrate.