Packaging and microcooling of high power diode laser bars

Lifetime and reliability of high power diode laser bars (HPDLBs) are sensitively related to operating temperature, mounting stress and solder electromigration. These three factors have been taken into account for the development of a new packaging technology for 1 cm laser bars of gallium arsenide. We examine the use of chemical vapour deposited (CVD) diamond as heatspreaders in order to reduce thermal resistance of a microchannel cooler for liquid cooling. We show that it´s possible to perform hard soldering on CVD-diamond with a new technique. Additionally, we present a controlled water cooling system fit to the flow characteristics of the cooler. It permits to adjust the emission wavelength of the diode lasers by changing the water flux.