Numerical modeling of the influence of temperature and driving current on “smile” in high power diode laser arrays

“Smile” in high power diode laser arrays is mainly caused by thermal stress generated during packaging processes and operation. By numerical modeling, a three-dimensional finite element model of a conduction-cooled packaged 60W high power diode laser array was established. Finite element method (FEM) was conducted to simulate and analyze the thermal and mechanical characteristic of the diode laser bar in different scenarios. According to the variation of thermal stress and displacement across the laser bar, the influence of temperature and driving current on “smile” was analyzed and discussed. Numerical simulation results show that “smile” will decrease with the increasing heatsink temperature and increase with the increasing driving current. In this paper, the corresponding quantitative relationships of smile with heatsink temperature and driving current were obtained. The work provides theoretical guidance for optimizing high power diode laser array design, packaging process and reducing “smile”.