Owing to the rapid progress in information technology, requirements for optical modules to be used in optical fiber communication systems are appreciably becoming sophisticated and demanding. To meet the stringent requirement for highly reliable and stable optical modules, we have specially developed a new laser-welder M800C, to realize low-distortion, high precision spot welding of optical modules.
Our novel laser cavity, designed to have highly rigid structure and good heat dissipation to alleviate thermal strain, has realized high laser output power stability, less than +/−0.6% of standard deviation value (4.6% peak-to-peak in 14,400 shots) in cyclic environmental temperature test from 5 to 35 degrees Celsius. In addition, we have developed a new laser-pulse-energy-dividing device by utilizing simple polarization dependent beam attenuators based on optical polarization for highly balanced dividing ratio. It can equally divide incident beam into three beams with less than +/−1.0% error for the typical output range used for spot welding. The real time digital laser pulse shape control was also adopted.
The above highly stable and equally balanced laser pulse ensures joining of high precision parts with high repeatability.