STTR Phase I: Predictive Molding of Precision Glass Optics

这个小型企业技术转移第一期项目旨在开发一种生产非球面玻璃光学元件的经济方法。用压缩成型法生产非球面玻璃光学器件目前还没有得到广泛应用。造成这种情况的主要原因之一是没有办法确定所需的模具几何形状来生产所需的光学几何形状。唯一可用的生产模具的方法是一个耗时且昂贵的试错过程，即制造精密的模具，对光学元件进行成型和检查，并使用最终光学元件中的错误来创建几何形状略有不同的新模具。这一过程反复进行多次循环，直到获得满意的模具几何形状；大大增加了过程的成本，需要很长的交货时间。该项目将开发基于物理的玻璃成型过程计算模型，根据模具几何形状、玻璃材料特性和成型参数的知识，准确预测光学器件的形状。该模型将通过系统地表征高温下玻璃的特性，将玻璃的粘弹性响应与模具和玻璃的热膨胀和弹性挠曲结合到该过程的计算模型中来开发。这个项目更广泛的（商业）影响将是许多消费设备，如DVD播放器、数码相机等，采用光学聚合物注塑生产的非球面光学元件。这是目前唯一能够以可接受的成本生产所需光学器件的技术。然而，由于其优越的光学特性，转向玻璃光学的压力越来越大，这将导致优越的设备性能。虽然玻璃模压成型广泛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器件的生产。在此建议中开发的计算工具将消除目前在发现生产公差光学所需的适当模具几何形状和加工参数之前生产许多昂贵的试验模具几何形状的需要。它将使玻璃光学模具能够以确定的方式生产，并消除采用该技术的最大技术障碍之一。这将使光电产品具有比现有产品更优越的性能。本文开发的方法将在其他精密成型和铸造工艺中有更广泛的应用。

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.