A backlight assembly for a display device is provided. The backlight assembly includes a transparent waveguide layer, a plurality of light sources, and a tunable grating layer. The light sources are arranged along an edge of the waveguide layer. Each light source transmits light into the waveguide layer through the edge. The grating layer is coupled to the waveguide layer, and has multiple rows. Each row of the grating layer is segmented into a series of cells so the grating layer is sectioned into an array of cells. Each cell is independently controllable to either not extract incident light received from within the waveguide layer, or to extract the incident light for emission from the backlight assembly. In another configuration, the waveguide layer is not present, and the light sources transmit light directly into an edge of the grating layer.