The invention is a side-emitting illumination system that incorporates a light emitting diode. The side-emitting illumination system recycles a portion of the light internally generated by a light emitting diode back to the light emitting diode as externally incident light. The light emitting diode reflects the recycled light, thereby increasing the effective brightness of the light emitting diode. The light reflected by the light emitting diode is directed though the output aperture of the side-emitting illumination system, thereby increasing the output brightness and efficiency of the side-emitting illumination system. The light emitting diode reflects externally incident light with a reflectivity greater than 40 percent.