Optical surface metrology with spatially and temporally partially coherent light wave fields, Application transfer (OPaL:Transfer)

自由曲面光学元件的面形检测是光学工业中质量保证的必要前提。特别是，具有成本效益的，精确和灵活的非球面测量仍然是一个未解决的挑战。在DFG资助的研究项目OPAL及其后续项目OPAL II的范围内，对基于剪切干涉测量的自由曲面检测方法进行了研究。通过多孔径剪切干涉测量（MArS），开发了一种允许同时使用多个独立光源的方法。这使得尽管成像光学器件的受光角受限，但利用光源的相应分布，不仅完全捕获具有相对大直径的球形测试对象，而且完全捕获具有相对大直径的非球形测试对象。通过这种方式，该方法结合了大的照明孔径和几何光学方法的灵活性，如偏转测量与干涉测量方法的高精度。透射和反射测量显示了MArS的潜力。OPAL前身项目的合作伙伴与Mahr GmbH公司一起在该转移项目的框架内将该方法进一步开发为原型。该项目的总体目标是在面向实践的环境中测试上述方法，并将其进一步发展为一个示范应用背景下的相应测量系统。对于在应用中的实施，特别感兴趣的是可以测量哪些测试对象类型，可以减少测量时间的程度以及设置过程和处理的复杂程度。为了实现项目目标，有必要确定MArS测量布置对相关应用的适应性的限制。重要的实践指导方针是记录尽可能不同类型的测试对象，实现短的测量时间，易于操作和成本方面。这导致了该项目的以下子目标：必须利用以前项目的经验，使测量安排适应相关的应用场景，并实施相应的演示，从而对直径最大为76 mm（3“）的非球面测试对象进行测量。为此，测量时间小于5分钟的有效测量和评估过程以及使用尽可能少的参考对象的设置过程必须允许对尽可能不同类型的测试对象进行测量。要实施的校准过程应能够使用成像系统中的标准光学器件将测量不确定性降低到50 nm以下。

The areal optical shape detection of freeform optics is an essential prerequisite for quality assurance in the optical industry. In particular, the cost-effective, precise and flexible measurement of aspheres still represents an unsolved challenge. Within the scope of the research project OPAL funded by the DFG and its continuation OPAL II, methods based on shear interferometry were investigated in relation to the detection of freeform surfaces. With the Multiple Aperture Shear Interferometry (MArS), a method was developed which allows the simultaneous use of several independent light sources. This makes it possible, despite a restricted acceptance angle of the imaging optics, with a corresponding distribution of the light sources, to completely capture not only spherical but also aspherical test objects with a relatively large diameter. In this way, the approach combines the large illumination aperture and flexibility of geometrical-optical methods such as deflectometry with the high precision of interferometric methods. Measurements in transmission and reflection showed the potential of MArS.The approach is now to be further developed into a prototype within the framework of this transfer project by the partners of the OPAL predecessor projects together with the Mahr GmbH company. The overall goal of the project is to test the approach described above in a practice-oriented environment and to further develop it into a corresponding measurement system in the context of an exemplary application. For the implementation in an application, it is of particular interest which test object types can be measured, how far the measuring time can be reduced and how complex the setup process and handling are.In order to achieve the project goal, it is necessary to determine the limits of the adaptability of the MArS measuring arrangement to relevant applications. Important practice-oriented guidelines are the recording of as different types of test objects as possible, the achievement of short measurement times, ease of operation and cost aspects. This results in the following sub-goals for the project: The experience from the previous projects must be used to adapt measurement arrangements to relevant application scenarios and to implement corresponding demonstrators, whereby measurements should be made on aspherical test objects with diameters of up to 76 mm (3 "). For this purpose, an efficient measurement and evaluation process with a measurement time of less than 5 minutes and a set-up process that uses as few reference objects as possible must allow measurements on as different types of test objects as possible. The calibration process to be implemented should enable the measurement uncertainty to be reduced to below 50 nm using standard optics in the imaging system.