A light emitting device disclosed herein includes at least one light source and an array of coupling lightguide strips continuous with a lightguide region of a lightguide formed from a film, light extraction features, a cladding layer in the light emitting region of the film, and a light input surface defined by the stacked bounding edges of the coupling lightguide strips, wherein an area percentage of the light input surface comprising a core region is at least 98 percent. In another embodiment, the light from the at least one light source is not directly coupled into the cladding layer at the light input surface. In a further embodiment, a total thickness of the coupling lightguide strips at the light input surface is less than (n) times a thickness of the lightguide region of the lightguide where (n) is the number of coupling lightguide strips.