Wafer-fused thin film cooler semiconductor laser structures

We examine the cooling requirements and temperature stabilization needs of semiconductor lasers with emphasis on vertical cavity surface emitting laser (VCSEL) arrays. Semiconductor lasers in both in-plane and vertical cavity geometries are capable of generating large heat power densities of the order of kW/cm² over areas as small as 100 μm². When cooling of the laser is needed, the cooler should be able to provide similar amounts of heat pumping. For these large amounts of heat pumping, a thin-film cooler structure is needed, especially if individual devices of an array must have precise temperature stabilization. Integration of the laser and thin film cooler by Au-Au wafer fusion is proposed. The fusion of the two interfaces is accomplished by mass transport in the deposited Au-films, which can be achieved under pressure at elevated temperatures. The quality of the fused interface is studied and preliminary experimental results are presented