Holographic Coatings for Telescopes

在过去的一年里，物理光学公司（POC）一直在 成功地制造了用于紫外线的全息皱纹结构， 可见光和非常近的红外光谱区域。 这些 全息反射镜展示了激光损伤阈值， 比最好的介电多层涂层好5倍， 反射率超过99.9%。 该研究项目提出， 将全息褶皱技术扩展到 嗯到3嗯。 红外区全息记录过程 也应该产生超高的损伤阈值， 可扩展到非常大的光学器件。 所采用的全息过程 使用低温沉积方法和集成 带有光栅的全息涂层 这些光栅可以用作 光束采样器到输出耦合器。 一个简单的 制造工艺，低吸收特性， 记录介质，和一个示范辐射线束，使POC的 涂层工艺是一种理想的民用和军用新技术 应用. POC的方法将大大减少结构性 重量、热负荷和成本与现有涂层相比 技术，因为它可以应用于轻质基板， 如图形环氧树脂、聚酯薄膜、铝和超薄玻璃。 此外，委员会认为， 初步实验结果表明，涂层具有 无除草问题。

During the past year, Physical Optics Corporation (POC) has been successful in fabricating holographic rugate structures for the UV, visible, and very near IR regions of the spectrum. These holographic mirrors demonstrated laser damage thresholds which were 5 times better than the best dielectric multilayer coatings, with reflectivities in excess of 99.9%. This research project proposes to extend this holographic rugate technology to the region from 1 um to 3um. The holographic recording process for the IR region should also yield ultra high damage thresholds and be easily scalable to very large optics. The holographic processes employed use low temperature deposition methods and an integration of holographic coatings with gratings. These gratings can be used as beam samplers to output couplers. The potential for a simple fabrication process, low absorption characteristics of the recording medium, and a demonstrated radiation harness make POC'S coating process an ideal new technology for civilian and military applications. POC's approach will greatly reduce structural weight, thermal load and cost compared to existing coating technologies since it can be applied to light-weigh substrates such as graphic-epoxy, mylar, aluminum, and ultra-thin glass. Moreover, initial experimental results have demonstrated that the coating has no degrassing problem.