Thermal modeling and analysis of high power semiconductor laser arrays

With the continuous increase of the output power of semiconductor laser array, the heat generation in the active region also increases continuously, which influences the performances and lifetime of semiconductor laser array seriously. In order to improve the performances and lifetime, understanding of the thermal behavior of high power semiconductor laser array packages and optimizing the thermal performance are crucial. By means of numerical analysis, a three-dimensional thermal model has been established, and the static and transient thermal characteristics in continuous-wave (CW) and quasi-continuous-wave (QCW) modes also have been studied systematically for a hard solder, conduction-cooled-packaged 808nm semiconductor laser array. Based on the thermal modeling and analysis, the approaches to reduce thermal resistance have been proposed. The results show that: compared with copper-tungsten (CuW), adopting the copper-diamond composite material as the submount can decrease the thermal crosstalk behavior between emitters, and reduce the thermal resistance by about 30%. In addition, a novel thermal design for the packaging structure of the mounting heat-sink is demonstrated, which has the ability of reducing the thermal resistance of the devices significantly.