Effect of welding sequence on welding-induced-alignment-distortion in packaging of butterfly laser diode modules: Simulation and experiment

Controlling welding-induced-alignment-distortion (WIAD) and maintaining coupling efficiency is obviously the most challenging issue in assembling of fiber-optic components using laser welding. WIAD is the dominant barrier to having high packaging yields. Previous investigation has revealed that the WIAD in butterfly laser diode module packaging could be mitigated by properly choosing weld process parameters such as welding sequence. In this paper, the effect of welding sequence on WIAD is studied numerically by finite-element method (FEM) with a more realistic physics based laser welding model and experimentally by welding prototype butterfly packages. Results from both methods are compared. It is shown that the influence of welding process parameters on WIAD is significant and WIAD control is possible if proper welding sequence is employed.