Low SMILE vertically stacked laser bars enable kW modular line lasers

Low SMILE vertically stacked laser bars gold/tin (AuSn) soldered on nearly symmetrical micro channel coolers were designed, built and characterized. 96% of 200 measured SMILE (bowing) values are less than 2 μm. Twenty-one 5×1 vertical stacks have a divergence of 2.03mrad with a standard deviation of 0.19mrad after fast axis collimation. A line laser module was built with twelve 5×1 vertical stacks to produce 6 KW in a line geometry of 0.6 mm@1/e2 by 285 mm @85% and a line uniformity of 86%. Several laser line modules can horizontally be connected to form a wider line for glass surface treatment and thin film solar panel processing.