Integrated Power Conditioning for Laser Diode Arrays

For several years, the Laser Program at LLNL has been designing and building a variety of specialized compact laser systems 1. They offer extremely high energy densities for their size and are primarily used in medical and military applications where a high premium is placed on both reliability and compactness. These systems are based upon a 2 cm-x-2 em liquid cooled wafer (Fig. 1) that supports laser diode bars mounted along one edge. Depending upon the application, the laser diodes are fabricated to emit in the 640-nm to 970-nm range while being driven by electrical current pulses of 80-160 A. In some applications, their output is used either to directly irradiate an object or to pump a solid state rod or slab laser. These systems operate at high average power levels and require innovative modular cooling system in which the diode bars are mounted above a micro channel cooling strip2.