Vertically aligned LCD’s are best known as homeotropic liquid crystals with the LC molecules aligned perpendicular to the glass substrate surfaces. The black mode has crossed linear polarizers on the outside substrates to achieve extremely high contrast ratios with no voltage applied and is the most common device configuration. As voltage is applied, the molecules rotate from vertical to horizontal in relation to the glass substrates achieving grey scale light amplitudes. The normal black mode is highly achromatic as the LC essentially has zero birefringence and homeotropic LC devices are considered to have the highest contrast of any LC mode. This configuration’s dark state has the additional benefit of having high temperature stability. The final contrast level is defined by the quality of the linear polarizers.

Liquid crystal fluids that exhibit negative dielectric anisotropy are required for this mode and special alignment fluids. VA cells can be manufactured uniformly in mass volumes with thin glass. If low transmitted wavefront distortion is required, precision cells can be manufactured with polished glass substrates.