A grating-coupled light guide concentrates light and diffractively redirects the concentrated light at a non-zero propagation angle as guided light having a predetermined spread angle. The grating-coupled light guide includes a light guide, an optical concentrator, and a grating coupler. The optical concentrator is configured to concentrate light from a light source as concentrated light and the grating coupler is configured to diffractively redirect the concentrated light into the light guide as the guided light. Characteristics of the optical concentrator and grating coupler are configured in combination to determine the non-zero propagation angle and predetermined spread angle. A grating-coupled display system further includes an array of light valves configured to modulate emitted light as a displayed image.