A backlight may include a light guide and a light input. The light guide may have a light reflection surface and a light emission surface. The light input may include a diverging wedge having a narrow end and opposing side surfaces extending to the narrow end. A light source may be disposed adjacent to one of the opposing side surfaces and may emit light into the light input portion. A multilayer polymeric mirror film may be disposed adjacent to the opposing side surfaces but not in intimate contact therewith and may reflect more than 95% of visible light incident on the multilayer polymeric mirror film.