Study Of Key Technology Of Automatic Packaging For Butterfly Laser Diode Module

As the most common optical signal amplifier, butterfly laser diode module is one of the important components in photo-communication. But the expensive packaging cost is always the bottleneck, and extremely limits the development of photo-electricity industry. The main reason is the manual or half-automatic packaging process. To improve the automatic packaging level, two main technologies should be considered. One is the fiber coupling (fiber alignment) technology. The other is fiber fixing technology. To improve the fiber coupling technology, a multi-axis optical alignment stage with highly positioning ability should be equipped. Also a quick and stable fiber coupling algorithm should be applied. The obstacle of fiber fixing technology is post welding shift (PWS). Research works should be focused on how to reduce the PWS or how to compensate the PWS.This thesis deals with the fiber coupling and fiber fixing technology mainly based on four different sections. First researching aim is optical alignment stage. In now days many multi-axis optical alignment stage only have a closed loop for single axis but not for the whole stage. This kind of control strategy could not take the axis coupling error into account. And the fiber alignment time would be increased or the fiber output power would be decreased. In this thesis a whole closed loop position feedback system is designed for a 3-axies parallel micro-stage to compensate the axis coupling error influence. A dynamic model of the 6-PSS parallel micro-stage is also discussed. Also the working space and forward solution are discussed based on kinematic analysis. At last simulation results have proved that with a sliding mode controller the axis coupling error can be deleted and the position tracking ability of the micro-stage is well.Conventional sliding mode control has its two inherent drawbacks. The first one is chattering and the second one is the strict robustness boundary condition. So a improved discrete sliding mode controller should be designed for a computer control system. And the discrete sliding model predictive algorithm overcomes the shortcomings of the conventional sliding mode controller. By predicting the future sliding mode function value and combining feedback correction and receding horizon optimization approaches, a discrete-time sliding mode control law for tracking problem is constructed. With the designed control law, closed-loop systems have strong robustness to matched or unmatched uncertainties as they eliminate chattering. Numerical simulations illustrate the validity of the proposed algorithm.Currently most fiber alignment algorithms are only suitable for lateral axes, and for angular alignment. Manual coupling is still widely used in product line. In recent years, engineers have tried to apply some automatic algorithms such as Hill-climbing algorithm to realize angular alignment. But since the pivot point is not always the end point of the fiber tip, an angular movement will cause an extra offset in lateral axis. Consequently, the whole alignment process will cost much more time. In this thesis, a novel automatic angular alignment method based on phase angle tracking is presented. Phase angle tracking is used to detect the optical power increasing direction and drive the collimator to the maximum power point. Experimental results show that the novel automatic angular alignment method can reduce the total time less than 160 seconds. It is obvious that this method is rapidly improved the efficiency in optical collimators assembly.Post welding shift can not be fully eliminated. But by optimizing some welding parameters, the PWS can be compensated or minimized. Based on enough welding experiments and the analysis by FEM, influence factors of PWS are studied, such as pre-welding shift, welding spot position, welding laser energy and initial position respectively. A BP neural network is constructed for analyzing efficiently the welding data, so that PWS can be predicted before welding. And then the fiber could be moved to an anti-direction shift of the predictive PWS. After welding the anti-direction shift will compensate the PWS. The experiment can validate that the PWS can be compensate into 0.4μm...