High Power Density Diode Laser Stack Array Packaging And Coupling Technology

The manufacturing technology of diode laser bar and the packaging process are two main processes of high-power diode laser technology. The epitaxial techniques for crystal growth have been developed during the last decades. For high-power laser diodes, epitaxial growth of III-V semiconductors, especially GaAs, plays a vital role. Today, crystalline growth out of the gas phase is preferred. Among these techniques, MOVPE and MBE are most commonly applied since they offer a valid control of composition and thickness of the deposited layers and thus allow for the fabrication of complicated laser structures. High power diode laser packaging techniques become the key in development of diode laser.In this thesis, the two key techniques, the packaging of high power diode laser and the beam coupling, have been studied; the large power diode laser beam-coupling module was designed and studied by experiment.The main results are as follows:1.In the research of high power density diode laser packaging techniques, the radiating effect of high efficient cooler is analyzed for several different packaging techniques, and the copper microchannel cooler has been determined to be the optimal choice in continuous wave DL packaging technique;2.By the research on the matching character of thermal expansion coefficient of the heat sink material and the laser bar material, the different characteristics of hard solder and soft solder were analyzed, The mismatch of thermal expansion coefficient lead to the mechanical stress during the soldering process, and the influence on DL bar was also analyzed. At the time, precision welding technology was analyzed, then the significances of heat-factor on stabilize technology and ensure welding quality during the welding were analyzed.3.High efficient coupling technique, beam-shaping technique and transmission technique are the key techniques in the extensive application of high power DL. The beam characteristic of diode laser and the critical facts, which effect coupling efficiency, were analyzed. Incoherent coupling of several individual elements can be implemented via polarization multiplexing, wavelength multiplexing and spatial multiplexing. The aim of all beam combination methods is to increase the power of the system while maintaining the beam quality and thus increasing the brightness of the system.4. The project designing of high power density DL stack were designed, and a 630W out-power stack module was packaged by principium experiment, Incoherent Beam superposition obtains a better experiment result, coupling efficiency is more than 90%.