Automatic Microwaveguide Coupling Based on Hybrid Position and Light Intensity Feedback

The microwaveguide coupling is a critical process to manufacture precise optical elements and optical devices, which are widely used for sensing. During the coupling process, the microwaveguides should be matched well to ensure the amount of light as much as possible. However, the used light will inevitably disturb the recognition of position while using the machine vision technology. Even if the microwaveguides can be well aligned based on the position, the amount of light may still fail to be maximum due to the fabrication error. Hence, achieving accurate and efficient alignment of microwaveguides remains unreachable in previous works. To tackle the above challenges, we present a robotic micropositioning system as well as the corresponding control strategy based on a hybrid position and light intensity feedback. In this study, a microrobotic positioning system with three degrees of freedom is first developed and integrated with optical microscopy. Then the optimal trajectory for coupling including obstacle avoidance is designed. After that, a model-free adaptive controller is proposed to guarantee the tracking precision. Last, simulation and experimental results demonstrate that the proposed system can achieve the coupling of the microwaveguides with 300.41% sensitivity improvement over the traditional method with single position feedback. This study provides a general solution to the assembly problem for the optical devices, and will have a long-term positive impact on the micromanufacturing field.