  A theoretical approach for uniformly extracting light propagating through a
light guide plate is developed here. Typically, liquid crystal display
modalities utilize a backlit lighting system illuminated from the edge with
light emitting diodes. The backlight acts as a light guide plate and is coupled
with a diffuser sheet along the surface to uniformly extract the light. Our
approach employs sub-micron diffraction gratings and eliminates the need for
diffuser sheets, while ensuring the uniform extraction of light. The physical
dimensions of the grating are varied along the surface of the light guide plate
to control the diffraction efficiency, thus determining the local viewing angle
and emitted intensity.
