Abstract: A composite laser diode enclosure, and a method of making the same, having a first enclosure sealed within a second enclosure. Each enclosure having a thermally conductive base plate, a side wall band attached to the base plate, and a lid attached to the side wall band to hermetically seal each enclosure. The materials forming the side wall band and lids are selected so that high quality metallurgical bonds are formed between the base plates and the side wall bands, and between the side wall bands and the lids. The first enclosure contains a laser diode, coupling optics, and input ends of optical fibers for delivering the laser diode output out of the enclosures. The second enclosure contains the first enclosure, TE coolers, thermistors, and a PC board with an optical detector, E-prom, interlock circuit and voltage protection circuit. Thermistors monitor the temperature of each enclosure.