Advanced Diode Laser Packaging

"Diode pumped solid state lasers are starting to be used in many military vehicles, including, missiles, unmanned aerial vehicles (UAV), and aircraft platforms. The military applications include laser radar systems, laser designators, and opticalcountermeasures. All of these systems require high power, very efficient, rugged, and low cost laser diodes to pump the solid state lasers.While laser diode bars with output power up to 80 W cw have been produced, commercial 50 W and higher cw laser diode bars have not demonstrated good reliability or long lifetimes. This is likely caused by the additional heat load and temperature risesuffered by these diode bars when mounted with conventional "copper block" techniques. Clearly the limits of conventional diode bar mounting technology are being approached.What is needed is a new packaging technology for high power laser diode bars. Materials should be used that have higher thermal conductivity than copper, and a coefficient of thermal expansion that is more closely matched to Gallium Arsenide. Inaddition, mechanical registration of the laser diode would reduce labor time for packaging, further reducing unit cost. After development of advanced packages, these new, high power laser diode bars will be used in many military applications, as well as commercial applications including materials processing, laser projection display systems, and in next generationphotolighograpy light sources."