A backlight includes a lightguide having a light emission surface, a first
light input surface, a second light input surface opposing the first
light input surface, and a lightguide thickness. A plurality of
antireflection features are on or in the first light input surface and
second light input surface. Each antireflection feature has a base length
value and a height value that are less than the light guide thickness. A
right eye image solid state light source is positioned to provide light
into the first light input surface and a left eye image solid state light
source is positioned to provide light into the second light input
surface.