The invention relates to a radiation source, in particular a light curing device, for the polymerization of dental materials, comprising a light conductor and a light generation device which has at least two light sources, preferably semiconductor light sources, in particular light diodes, and the radiation of which is bundled by a reflector and fed into the light conductor. The light sources differ from one another with respect to their light color and/or their emission spectrum and are controllable separately for changing the light color and/or the emission spectrum and/or the spectral radiant power of the radiation emitted. The light conductor has at least one monocore section and one multicore section wherein the radiation emitted by the light sources is fed into a monocore section of the light conductor. Further, the invention relates to a light-conducting device for a radiation source or a light curing device of this kind.
