A light source device for endoscopic or exoscopic applications includes a flat first light source, a second light source, an illuminating beam path that is configured to provide a first light beam emanating from the first light source for an endoscopic or exoscopic application, and a coupling device to couple a second light beam from the second light source into the illuminating beam path, whereby the coupling device is configured in such a way that at the coupling site the cross-section surface of the second light beam is smaller than the cross-section surface of the first light beam.