A Quantitative Postweld Shift Measurement and Compensation Technique in Butterfly Laser Module Packages

A quantitative postweld shift (PWS) measurement and compensation technique employing a high-magnification camera with image capturing system (HMCICS) in butterfly-type laser module packages is investigated. The results show that the direction and magnitude of the fiber alignment shifts induced by the PWS in laser-welded butterfly-type laser module packaging can be quantitatively determined and compensated. The measured coupling powers in laser module packages after welding and compensation were clearly confirmed the measured fiber shifts that determined by the translational and rotational parameters. Therefore, the fiber shifts due to the PWS could be realigned back closer to their original optimum position after applying welding compensation, and hence the coupling powers loss due to the PWS could be regained. In comparison with previous studies of the PWS compensation by the well-known mechanical adjustment through a qualitative estimation technique, this HMCICS technique has successfully provided the mechanical adjustment through a quantitative compensation to the effect of the PWS on the fiber alignment shifts in butterfly-type laser module packages. The reliable butterfly-type laser modules with high yield used in lightwave transmission systems can be developed and fabricated.