【作者】 余卿；

【导师】 余晓芬；

【作者基本信息】 合肥工业大学 ， 测试计量技术及仪器， 2011， 博士

【摘要】 激光共焦显微术是现代加工制造、生物医学等领域中探知样品表面微形貌的重要技术手段之一。本学位论文选题来源于国家自然科学基金——基于并行像散共焦探测原理的微结构三维形貌测量基础研究（50775063），重点研究激光并行光源，克服由于泰伯效应给测量带来的影响，并构建柔性的数字并行光源，提高共焦测量速度，扩展共焦测量用途。激光用于并行共焦测量系统可以提高测量分辨率，因泰伯效应会产生多个共焦像，致使无法辨识正焦面位置，使测量无法实现；针孔阵列、微透镜阵列等均能实现光束分割，用于并行共焦测量，但是这些光分束器件普遍存在制作困难、价格昂贵等缺点，而且器件一旦制作完成，其参数将不能更改，因而对不同的被测对象的适应性较差。因此，本论文围绕激光并行共焦测量中的并行光源开展了系统深入的研究，主要的研究工作和创新点如下：（1）建立了激光并行共焦测量的泰伯间距模型在菲涅耳衍射光学的基础上，建立了激光并行共焦测量系统的泰伯间距模型，推导了系统中的物方泰伯间距公式，指出了物方泰伯间距zT与光源波长λ、光分束器件周期d，以及望远镜组视觉放大率Г之间的关系：zT=(dГ)2/λ，为研究克服泰伯效应对测量影响的方法提供了理论依据。（2）提出了多种克服泰伯效应影响的方法泰伯间距计算数学模型表明：减小光源的波长λ、扩大光分束器件的周期d、增加望远镜组的视觉放大率Г均可扩大泰伯间距。在此基础上，提出了多光源系统、双光源系统，以及采用微透镜阵列与针孔阵列的合成光分束器件等多种测量系统构建方案，较好地克服了泰伯效应对激光并行共焦测量的影响。上述研究成果已申请1项国家发明专利。（3）建立了基于数字微镜器件的柔性并行光源的空间光调制模型建立了数字微镜器件（DMD）在相干光照射下的反射及衍射模型，得到了DMD经调制后形成的光场是一个包含了DMD自身的衍射图像、DMD所显示图像的实像、虚像的复杂二维周期性光波场的结论，证明了若仅利用DMD所成的点光源阵列实像，则激光并行共焦测量可不受泰伯效应影响，并由此提出了“单光源双光路”的激光并行共焦测量系统构建方案，并申请了1项国家发明专利。（4）构建了基于数字微镜器件的激光并行共焦测量系统研究了基于DMD的柔性数字光源构建方法，通过操作者的简单设置，即可控制生成任意尺寸和间距的点阵列光源、栅状光源以及混合光源，既降低了阵列光源制作成本，又能根据不同的被测对象制定不同的测量策略，扩展了并行共焦测量的应用范围。该研究成果已申请1项国家发明专利，获得1项实用新型专利。（5）研制了单光源双光路激光并行像散共焦测量装置并完成了相关实验研究较系统地分析了光源、光分束器件、CCD及其他光学器件特性对测量的影响，搭建了单光源双光路激光并行像散共焦测量实验装置，研究了抑制系统构建误差导致的光点漂移影响的图像处理方法，提高了数据处理精度及可靠性。实验结果表明：利用基于DMD的并行光源可以辨识出正焦面位置，克服泰伯效应对测量的影响；利用基于微透镜阵列的并行光源可以实现高精度测量。更多还原

【Abstract】 Laser confocal microscope is one of the important technologies to measure the3Dsurface topography of specimens in modern manufacturing and biomedical engineering. Thisdissertation was based on the project of “Research on Measuring3D Surface Topographyof Microstructure Based on the Principle of Parallel Astigmatism Confocal Detection”sponsored by the National Natural Science Foundation, and it focused on laser parallelsource to overcome the influence of Talbot effect in the laser parallel confocalmeasurement. A flexible digital parallel light source has been developed to improve thespeed and to extend the use of confocal measurement.When laser is used in parallel confocal measurement system, the resolution could beimproved, but the Talbot effect which causes lots of confocal images will appear. However,only one of those images could be called in-focus image. If the in-focus image cannot berecognized, the confocal measurement will not be realized. Many optical divide devices(ODDs), like pinhole array and microlens array, can divide a light beam into many finebeams, but those ODDs have poor adaptability to different measured object because theirparameters could not be changed, and in addition, they are difficult to manufacture, andthe prices are too high.In this dissertation, the parallel light source used in laser parallel confocalmeasurement has been studied systematically, and the main researches and innovations ofthe dissertation can be summarized as follows:(1) Established the Talbot distance model in laser parallel confocal measurementThe Talbot distance model in laser parallel confocal measurement based on FresnelOptics has been established, and the formula of Talbot distance in object space has beenderivated. The formula built the relationship among Talbot distance in object space,wavelength of laser, period of ODD, and visual magnification of telescope: zT=(dГ)2/λ.It will provide the theoretical basis to overcome the influence of Talbot effect in the laserparallel confocal measurement.(2) Developed some methods to overcome the influence of Talbot effectThe formula of Talbot distance in object space indicated that the Talbot distancecould be expanded by reducing the wavelength of laser, expanding the period of ODD, andincreasing the visual magnification of telescope. The thesis developed some projects, suchas Multi-source system, Dual-source system, and synthesis ODD based on pinhole arrayand microlens array, to suppress the impact of Talbot effect in a certain extent. One invention patent has been applied.(3) Established the spatial light modulation model of flexible parallel light sourcebased on Digital Micromirror DeviceThe reflection and diffraction models of Digital Micromirror Device (DMD) havebeen established by illuminating by coherent light, and the results indicated that the lightwave field after modulated was a complicated2D periodic light wave field, whichcontained a diffraction image of DMD itself, and real and virtual images of displayedpicture on DMD. Furthermore, the laser parallel confocal measurement would not beinfluenced by the Talbot effect when only the real image of displayed picture on DMD wasused, and a project of laser parallel confocal measurement system based on “single sourceand dual beam paths” was developed. One invention patent has been applied.(4) Constructed a laser parallel confocal measurement system based on DMDThe flexible digital light source based on DMD was studied, which could producepoint light array with different size of point and different distance between points, and alsocould produce grid light source. This flexible light source could help saving cost,developing different measurement strategies to different objects, and expanding the use ofparallel confocal measurement. One invention patent has been applied, and one utilitymodel patent has been obtained.(5) Developed a laser parallel astigmatism confocal measurement system based on theparallel light source with single source and dual beam paths, and completed relatedexperimentsThe influence on measurement from laser, ODD, CCD and other optical devices wasanalyzed systematically, and a laser parallel astigmatism confocal measurement systembased on the parallel light source with single source and dual beam paths was constructed.A method of image processing to inhibit drifting of measured spots, which is caused by theerror of system construction, was investigated, and this method could help improve theprecision and reliability of data processing. The experiments results indicated that theposition of in-focus image could be distinguished with the parallel light source of DMD,and high precision measurement could be completed with the parallel light source ofmicrolens array.更多还原