Non-corrosive micro cooler with matched CTE

New technology regarding manufacturing of micro cooling systems and selective laser melting was presented at Photonics West 2005; at Photonics West 2006 the first non-corrosive active micro coolers manufactured by this procedure were introduced to the auditorium. This presentation shows the latest results regarding active micro cooling systems for high power diode laser with a matched CTE. After the first non corrosive micro coolers passed the tests regarding cooling performance, there were still two tasks which had to be accomplished: First one was the homogeneity of cooling. In order to achieve the homogeneity, the design of the supporting structure in front of the micro cooling structures was modified. Measurements of cooling performance and the range of the wavelength along the laser bar showed that with the modified structure a homogeneous inflow was achieved as well as homogeneous cooling along the laser bar. The presentation highlights the measurements and result s. Second point of development was the quest for a material combination with an adequate thermal conductivity for keeping the cooling performance, but with a coefficient of thermal expansion that matches with the CTE of diode laser bar material. After testing several materials fining to these requirements, only one material was left, which was capable to machine workable micro coolers with the SLM procedure. The presentation contains the first results of the micro coolers with a matched CTE regarding thermal resistance, CTE and packaging with gold - tin solder.