STTR Phase I: Predictive Molding of Precision Glass Optics

本小企业技术转让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。通过压缩成型生产非球面玻璃光学器件目前还没有被广泛实践。其主要原因之一是没有方法来确定所需的模具几何形状以生产所需的光学几何形状。生产模具的唯一可用方法是耗时且昂贵的试错过程，其中制造精密模具，模制和检查光学器件，并且使用所得光学器件中的误差来创建具有略微不同几何形状的新模具。该过程反复地持续许多循环，直到获得令人满意的模具几何形状;显著地增加了过程的成本并且需要长的交货时间。该项目将开发基于物理学的玻璃成型过程的计算模型，该模型可以根据模具几何形状，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。该模型将通过对玻璃在高温下的特性进行系统表征来开发，将玻璃的粘弹性响应与模具和玻璃的热膨胀和弹性变形结合到该过程的计算模型中。该项目的更广泛（商业）影响将是许多消费设备，如DVD播放器，数码相机等，其结合了通过光学聚合物注射成型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，由于玻璃光学器件的上级光学特性，其将导致上级器件性能，因此转向玻璃光学器件的压力越来越大。虽然玻璃成型广泛用于生产容器和其他低公差物品，但目前尚未广泛用于生产精密光学器件。在此建议中开发的计算工具将消除目前需要生产的许多昂贵的试验模具几何形状之前，发现适当的模具几何形状和加工参数所需的生产公差的光学。它将使玻璃光学模具能够以确定性的方式生产，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目前更优越的上级性能。本文所提出的方法对其它精密铸造工艺也有较广泛的应用。

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.