Abstract: An electrodeless discharge lamp includes an electrodeless lamp bulb enclosing a fill which emits light when excited, an excitation structure positioned near the bulb and adapted to excite the fill, a rotation assembly connected to the bulb and adapted to rotate the bulb during operation of the lamp, and a plurality of structures formed on an outer surface of the bulb adapted to enhance cooling of the bulb. In some cases the structures are distributed in accordance with a temperature profile of the bulb to provide a relatively more uniform bulb temperature during operation. Some structures include protrusions which are distributed around the entire surface of the bulb. Some structures include protrusions which are distributed around the entire surface of the bulb except in the region of the bulb equator. Some structures include a plurality of ribs attached to an outer surface of the bulb, wherein the ribs are aligned transverse to a plane of the equator of the bulb.

Abstract: An improved electrodeless discharge lamp bulb includes an integral ceramic reflector as a portion of the bulb envelope. The bulb envelope further includes two pieces, a reflector portion or segment is cast quartz ceramic and a light transmissive portion is a clear fused silica. In one embodiment, the cast quartz ceramic segment includes heat sink fins or stubs providing an increased outside surface area to dissipate internal heat. In another embodiment, the quartz ceramic segment includes an outside surface fused to eliminate gas permeation by polishing.