A light source which may be used as part of a dental curing lamp is comprised of at least one, and preferably a plurality, of LEDs. To increase the efficiency of the light output the LEDs are encapsulated in a beam converger including an extractor portion and a collimator portion. Light rays leaving the collimator portion have an angle which matches the entrance angle input requirements of an associated light guide. In another aspect, cooling of LEDs is accomplished by reservoirs located in a hand piece and in a base station. In another aspect of the invention, cooling is achieved by use of a heat pipe and a cooling jacket. The cooling jacket may contain a material having a high latent heat of fusion at a phase change temperature suitable for cooling the LEDs.