STTR Phase I: Predictive Molding of Precision Glass Optics

这个小型企业技术转移第一阶段项目旨在开发一种生产非球面玻璃光学元件的经济方法。通过模压成型生产非球面玻璃光学元件目前还没有得到广泛的实践。其主要原因之一是不存在确定所需模具几何形状以产生所需光学几何形状的方法。用于制造模具的唯一可用的方法是耗时且昂贵的试错过程，由此制造精密模具，模制和检查光学元件，并且使用所得到的光学元件中的误差来创建具有略微不同的几何形状的新模具。这一过程反复进行多次，直到获得满意的模具几何形状；这大大增加了过程的成本，并需要较长的交货期。该项目将开发基于物理的玻璃成型过程的计算模型，通过模具几何知识、玻璃的材料属性和成型参数准确预测光学元件的形状。这些模型将通过系统地表征玻璃在高温下的性质，将玻璃的粘弹性响应与热膨胀和模具和玻璃的弹性偏转纳入到过程的计算模型中来开发。该项目将产生更广泛的(商业)影响，许多消费设备，如DVD播放机、数码相机等，结合了通过注塑光学聚合物产生的非球面光学元件。这是目前唯一能够以可接受的成本生产所需光学元件的技术。然而，由于其优越的光学性能，转向玻璃光学的压力越来越大，这将导致卓越的设备性能。虽然玻璃模压被广泛应用于容器和其他低公差物品的生产，但目前还没有广泛用于精密光学的生产。在此方案中开发的计算工具将消除目前生产许多昂贵的试模几何形状的需要，然后才能找到合适的模具几何形状和生产公差光学元件所需的工艺参数。它将使玻璃光学元件的模具能够以确定性的方式生产，并消除采用这项技术的最大技术障碍之一。这将使光电产品具有比目前可用的产品更优越的性能。本文提出的方法将在其他精密成型和铸造工艺中得到更广泛的应用。

This Small Business Technology Transfer Phase I project aim to develop an economical method for production of aspheric glass optical elements. Production of aspheric glass optics by compression molding is currently not widely practiced. One of the primary reasons for this is that no method exists to determine the required mold geometry to produce a desired optic geometry. The only available method for producing molds is a time-consuming and expensive trial and error process whereby precision molds are fabricated, optics are molded and inspected, and errors in the resulting optic are used to create new molds with slightly different geometry. This process continues iteratively for many cycles until a satisfactory mold geometry is obtained; adding significantly to the cost of the process and necessitating long lead times. This project will develop physics based computational models of the glass molding process that accurately predict the shape of the optic from knowledge of the mold geometry, the material properties of the glass, and the molding parameters. The models will be developed through systematic characterization of the properties of glasses at high temperatures, incorporation of the the viscoelastic response of the glass with thermal expansions and elastic deflections of the mold and glass into computational models of the process.The broader (commercial) impacts from this project will be many consumer devices, such as DVD players, digital cameras, etc., incorporate aspherical optical elements produced by injection molding of optical polymers. This is currently the only technology capable of producing the required optics at acceptable cost. However, there is increasing pressure to move to glass optics due to their superior optical properties, which will result in superior device performance. While glass molding is widely practiced for production of containers and other low tolerance items, it is not currently widely used for the production of precision optics. The computational tools developed in this proposal will eliminate the current need for production of many expensive trial mold geometries before discovering the proper mold geometry and processing parameters required to produce in-tolerance optics. It will enable molds for glass optics to be produced in a deterministic manner and remove one of the largest technological barriers to adoption of this technology. This will enable opto-electronic products with superior capabilities compared to those available today. The methods developed here will have broader application to other precision molding and casting processes.