PLYMOUTH, Mich. -- Developer and manufacturer of high-performance laser beam sources, Rofin-Sinar Technologies Inc., has announced its agreement to purchase 80 percent of the stock of Hamburg, Germany-based Dilas Diodenlaser GmbH. Dilas specializes in packaging and cooling laser diodes, and manufacturing multiple-kilowatt diode laser systems for materials processing applications and diode lasers for medical, research, inspection and measurement instruments. With this acquisition, Rofin-Sinar will be adding technology and a new product line to its wide range of industrial lasers and hopes to speed up the introduction of new diode-based laser systems for materials processing applications. Typical materials processing applications for diode lasers are soldering and welding of plastic and thin metals, and pumping solid-state lasers. The strong market growth potential for these devices -- projected to grow from $6 million in 1996 to $9 million in 1997, according to Rofin-Sinar -- is credited to their miniature size, higher efficiency compared with conventional laser designs, easy integration and the possibility of coupling their output into fiber optics.