We present a unified electromagnetic modeling of coherence scanning interferometry, confocal microscopy, and focus variation microscopy as the most common techniques for surface topography inspection with micro- and nanometer resolution. The model aims at analyzing the instrument response and predicting systematic deviations. Since the main focus lies on the modeling of the microscopes, the light–surface interaction is considered, based on the Kirchhoff approximation extended to vectorial imaging theory. However, it can be replaced by rigorous methods without changing the microscope model. We demonstrate that all of the measuring instruments mentioned above can be modeled using the same theory with some adaption to the respective instrument. For validation, simulated results are confirmed by comparison with measurement results.

采用数字光栅投影技术对强反射表面物体进行形貌测量时，由于采集的图像出现局部过明或过暗的现象，造成测量精度下降。基于此，提出一种改进的自动多次曝光图像融合技术，首先通过系统灰度响应曲线确定合适的测量灰度值范围，并根据基准点拟合出相机响应函数，计算出所需的曝光时长和次数；其次，将相机采集的不同曝光时长下光栅条纹图像与投射纯白图像下制作的掩膜图像相乘并进行线性变换叠加，采用对数变化提升叠加后光栅条纹图的暗部区域细节；最后通过解相计算出被测物的三维点云数据。实验结果表明，该方法可以准确计算出曝光时长和次数，融合后的图像条纹清晰完整，对于具有强反射表面的标准块、水泵压板护套和回程盘，点云重建率分别达到99.80%、99.20%、99.40%，提高了强反射表面的形貌测量精度。

脉冲压缩光栅是实现高能量激光的核心光学元器件，其制造过程中产生的表面污染物和微结构缺陷成为限制高功率激光系统发展的技术瓶颈，为了提升光栅的激光诱导损伤阈值，提出利用磁性复合流体进行脉冲压缩光栅（PCG）后处理抛光研究。对抛光前后光栅样品的微观结构，表面形貌、表面粗糙度、衍射效率和激光诱导损伤阈值等参数进行测量，进行抛光前后光栅表面质量和光栅性能的评估。研究发现，磁性复合流体抛光能够在不破坏实际光栅结构的前提下抑制加工过程产生的毛刺，微结构缺陷等；经3 min抛光后，光栅顶部表面粗糙度从21.36 nm下降到3.73 nm；激光诱导损伤阈值从2.8 J/cm²提高到3.8 J/cm²，抗激光损伤性能提升35.7%，且不影响衍射效率。实验结果表明：磁性复合流体抛光是一种可以提高光栅元件表面质量，提升光栅元件光学性能的有效方法。