基于菲涅耳数字全息术的物体位移测试研究

Research on Displacement Measurement of Object Based on Fresnel Digital Holography

对于物体位移的测试一直是工程领域中不可避免的问题。应用传统全息干涉术测试物体位移的方法处理过程复杂,测量结果精度低。数字全息是传统全息与现代电子技术相结合的一种数字化的光信息处理技术。文中将电荷耦合器件CCD与电寻址液晶EALCD相结合,实现数字全息的记录和再现过程。用数字的方式记录和处理全息图像,避免了传统全息照相的化学处理,利用数字图像处理技术来改善再现图像质量和提取有价值的信息。在数字全息实验理论分析的基础上,对反射式的被测物体进行了菲涅耳全息图的记录与再现,再现图像的清晰度和干涉条纹的对比度都得到了显著的改善。

The test of object displacement is always an unavoidable problem in the engineering field. The method of using traditional holographic interferometry to test the displacement of objects is complicated and the accuracy of measurement results is low. The digital hologram is a digitalization information process technology combining traditional holography and modern electronic technology. The process of digital holographic recording and reconstruction is realized through combining charge-coupled device （CCD） with electrically addressed liquid crystal display （EALCD）. Digital imaging processing technology is used to record and process holographic images to avoid traditional chemical processing. The quality of the reconstruction images is improved and the needed information is extracted. On the basis of theoretical analysis of digital holographic experiments, Fresnel holograms about reflecting measured objects are recorded and reconstructed, the clarity of the images and the contrast of holographic interferogram is significantly improved.