SBIR Phase II: High Dynamic, Alignment Free Metrological Method for 3D Shape Measurement of Optical Surfaces Based on Polarization

该小型企业创新研究第二阶段提案旨在开发一种新的免安装的MEMS交钥匙系统，专用于高测量速度和高动态范围的光学表面测量。下一代光学表面将需要大规模生产，具有高的球面形状和高数值孔径（非球面）。由于当今有限的计量方法，制造这些光学元件是具有挑战性的：接触式传感器太慢而不能在过程中使用，而干涉仪和波前传感器具有小的有限动态范围并且需要仔细对准。研究的目的是设计一个基于偏振的方法的原型，并评估其性能，速度，动态范围，精度，对准不敏感性。所提出的方法结合了一个创新的偏振相机，一个特定的照明，和一个新的算法自动3D形状提取。这项研究的结果是证明，所提出的方法导致非常低的灵敏度对准，快速的测量时间，高动态范围，和不确定性小于当前的制造公差。初步仿真结果表明，该系统可在40 ms内完成2”口径非球面透镜的测量，分辨率为10,000点，动态范围为20 mm，测量精度为0.25 μ m。该项目更广泛的影响/商业潜力将解决用于各种应用的非球面光学组件的日益增长的制造问题：用于太阳能发电的聚光光伏器件（CPV），光学仪器，眼科镜片和消费电子产品（相机，手机）。使用当前的计量工具控制非球面光学表面是耗时的过程。接触式传感器太慢，干涉仪具有严格的对准要求和低动态范围。由于以下原因，对对准不敏感、执行快速测量、具有高动态范围和良好精度的系统的商业潜力是极其有价值的。该系统将允许大规模生产高质量的非球面透镜，并对每个制造部件进行系统检查。高数值孔径透镜也可以很容易地在加工过程中测量，这将大大提高生产率。这将转化为更快地部署更便宜，更高效的太阳能发电，更轻的光学系统和更好的矫正隐形眼镜。目前的项目还将产生更广泛的影响，为基于偏振传感的新型计量学打开大门，该计量学未来也可应用于许多其他行业，如塑料、钢铁、玻璃、汽车、机器人、监控和医疗行业。

This Small Business Innovation Research Phase II proposal aims at developing a new alignment-free metrological turn-key system dedicated to the measurement of optical surfaces with high measurement speed and high dynamic range. Next generation optical surfaces will need to be mass-produced with high departure from spherical shapes and high numerical aperture (Aspheric). Manufacturing these optical components is challenging because of today's limited metrology methods: contact sensors are too slow to be used in-process whereas interferometers and wavefront sensors have a small limited dynamic range and require careful alignment. The research objective is to design a prototype of a polarization based method and to evaluate its performances; speed, dynamic range, accuracy, insensitivity to alignment. The proposed approach combines an innovative polarization camera, a specific illumination, and a novel algorithm for automatic 3D shape extraction. The result of this research is to demonstrate that the proposed approach leads to very low sensitivity to alignment, fast measurement time, high dynamic range, and uncertainty smaller than current manufacturing tolerances. Preliminary simulations show that 2" diameter aspheric lens can be measured in 40 ms, with a resolution of 10,000 points, a dynamic range of 20 mm and an accuracy of 0.25 micron root-mean-square (RMS). The broader impact/commercial potential of this project will address the growing manufacturing of aspheric optical components used for various applications: concentrating photovoltaics (CPV) for solar power generation, optical instruments, ophthalmic lenses and consumer electronics (cameras, phones). Controlling aspheric optical surfaces using current metrology tools is a time consuming process. Contact sensors are too slow and interferometers have tight alignment requirements and low dynamic range. The commercial potential of a system insensitive to alignment, performing fast measurements, with high dynamic range and good accuracy is extremely valuable for the following reasons. The system would allow mass production of high quality aspheric lenses with systematic inspection of each manufactured component. High numerical aperture lenses would also be measured easily in-process which will drastically increase productivity. This will translate into the faster deployment of cheaper, more efficient solar power production, lighter optical systems, and better corrected contact lenses. The present project will also have the broader impact of opening the door to a new kind of metrology based on polarization sensing, which could also be applied to many other industries such as plastics, steel, glass, automotive, robotics, surveillance and medical industries in the future.