High-Performance Durable Coatings for Large Astronomical Optics

适用于大型天文光学器件的高性能耐用涂层

• 批准号: 1005506
• 负责人: Andrew Phillips
• 金额: $ 49.16万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2014-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1005506&HistoricalAwards=false
• 关键词: Performance; Durable; Coatings; Large; Astronomical

With modern semiconductor detector arrays approaching near-ideal performance, the throughput of telescopes and their associated instrumentation is becoming limited by the coatings applied to the optical components. Mirror coatings must have the highest reflectivity attainable, be able to withstand extremes in temperature and humidity, be cleanable, and be as durable as possible. Transmissive optics (lenses), by contrast, require extremely low-reflectivity surfaces, yet the coatings to achieve these low light losses must also be essentially impervious to contaminants and periodic cleaning. Today's best coatings leave much to be desired in these regards. Aluminum is still the standard telescope mirror coating, despite losses as high as 10% in the optical red spectral region, while the best antireflection coating is soluble in water and therefore difficult to maintain.Astronomy is not the only discipline that would gain from improvements to optical coatings. Solar arrays and solar concentrators, for example, also benefit directly from better throughput, and the potential economic impact of a 10% gain in electrical conversion efficiency would be astounding, when considered on the worldwide market.Improvements in optical coatings require not only new and better formulations but also more uniform and reliable application techniques. The coatings lab at the University of California Observatories (Santa Cruz), headed by Dr. Andrew Phillips, has been engaged in efforts to improve both reflective and anti-reflection coatings for astronomical optics for a number of years. Starting with improvements to the infrastructure of their coating facilities, Dr. Phillips seeks to pursue two goals: a definitive comparison of the efficiency and uniformity of depositing coatings through the relatively new technique called "ion-assisted deposition" vs. the more traditional approach of "sputtering". The improvements will also extend their coating capabilities to include the reactive deposition of nitrides, which are critical to the highly reflective coating considered to be the current state of the art. A novel moving stage inside the vacuum chamber will also allow application onto large substrate areas with improved thickness and process uniformity. This same new equipment will be used to develop both high-performance protected-silver coatings for mirrors as well as multi-layer sol-gel anti-reflection coatings for large lenses. Funding for this work is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.

随着现代半导体探测器阵列的性能接近理想状态，望远镜及其相关仪器的吞吐量正受到光学元件涂层的限制。 镜面涂层必须具有最高的反射率、能够承受极端的温度和湿度、可清洁且尽可能耐用。 相比之下，透射光学器件（透镜）需要极低反射率的表面，而实现这些低光损失的涂层还必须基本上不受污染物和定期清洁的影响。 当今最好的涂料在这些方面还有很多不足之处。 尽管在光学红色光谱区域损失高达 10%，但铝仍然是标准的望远镜镜面涂层，而最好的减反射涂层可溶于水，因此难以维护。天文学并不是唯一可以从光学涂层改进中获益的学科。 例如，太阳能电池阵列和太阳能聚光器也直接受益于更高的产量，考虑到全球市场，电转换效率提高 10% 的潜在经济影响将是惊人的。光学涂层的改进不仅需要新的、更好的配方，还需要更统一和可靠的应用技术。 加州大学天文台（圣克鲁斯）的涂层实验室由 Andrew Phillips 博士领导，多年来一直致力于改进天文光学的反射和抗反射涂层。从改进涂层设施的基础设施开始，菲利普斯博士力求实现两个目标：通过相对较新的“离子辅助沉积”技术与更传统的“溅射”方法，对沉积涂层的效率和均匀性进行明确比较。 这些改进还将扩展其涂层能力，包括氮化物的反应沉积，这对于被认为是当前最先进技术的高反射涂层至关重要。真空室内的新型移动平台还可以将其应用到大面积基板上，并提高厚度和工艺均匀性。同样的新设备将用于开发用于镜子的高性能保护银涂层以及用于大型透镜的多层溶胶-凝胶减反射涂层。 这项工作的资金由美国国家科学基金会天文科学部通过其先进技术和仪器计划提供。