基于数字微镜的并行激光共焦显微检测技术研究

Research on the Technology of Parallel Laser Confocal Microscopy Detection Based on Digital Micromirror Device

为了对微纳加工工件进行三维形貌测量,建立了基于数字微镜的并行激光共焦显微检测系统。首先,利用衍射光学对数字微镜的夫琅禾费衍射模型进行了研究。接着,利用数字微镜实现扫描像素单元为2×2,周期为T=3的并行扫描模式。然后对三维图像重构算法和激光散斑匀化进行了分析。最后,利用该系统分别对镀膜平板、WSZ位置灵敏阳极探测器以及螺钉进行了三维测量。实验结果表明,在轴向平移台步距为10nm的条件下,该系统能准确重构出样品三维形貌。该共焦显微检测方法能大大提高共焦扫描速度,能很好地满足一般工业检测需求,本文为并行共焦检测技术提供了一条新的研究和应用方法。

In order to measure workpiecers micro-nano three-dimensional topography, a parallel confocal microscopy detection system based on digital micromirror device（DMD） is set up. Firstly, the Fraunhofer diffraction model of DMD is studied. Secondly, the parallel scanning model of 2 × 2 pixel unit and T= 3 is realized by the use of DMD. Then the three-dimensional image reconstruction algorithm and laser speckle homogenization is analyzed. Finally, the measuring system makes three-dimensional measurements for coated plate, WSZ position sensitive anode detector and screw respectively. The experimental results show that the three-dimensional reconstruction image is obtained under the condition that the stepping motor moves 10 nm per step. This parallel confocal microscopy system greatly improves the three-dimensional testing speed and can satisfactorily meet the general industrial testing requirement. It provides a new method of research and application for parallel confocal detection technology.