A light-emitting device which has a plate-shaped light guide (102) having front and rear surfaces (106, 108), being major surfaces, and edge surfaces (110, 112, 114, 116); and a light source (104) arranged at the plate-shaped light guide at such a position that the generated light is entered into the plate-shaped light guide and propagates in a substantial direction of propagation that is parallel with the front surface. At least a portion of the plate-shaped light guide includes a three-dimensional surface structure (118) arranged to provide a controlled light output through at least one of the front and rear surfaces and at least one of the edge surfaces. The controlled light output is controlled in terms of light output characteristics.