Establishing the design and development of novel crystalline-amorphous hybrid optical coatings for precision measurements and frequency standards

建立用于精密测量和频率标准的新型晶体-非晶混合光学涂层的设计和开发

• 批准号: ST/X004856/1
• 负责人: Stuart Reid
• 金额: $ 32.37万
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FX004856%2F1
• 关键词: Establishing; design; development; novel; crystalline

Optical coatings - typically consisting of multiple thin layers of alternating amorphous (glass-like) materials - are widely used to form highly reflective mirrors, efficient anti-reflective coatings or optical filters which allow particular wavelengths to be transmitted. Highly-reflective coatings are a key part of gravitational wave detectors. These instruments measure tiny changes in length caused by gravitational waves passing through the Earth, and have so far detected almost 100 astrophysical gravitational wave signals from merging black holes and neutron stars. Future, more sensitive detectors are planned to expand the capabilities of gravitational wave astronomy, and improving the performance of optical mirror coatings is a critical challenge for these new detectors. This project aims to combine a traditional multilayer optical coating with a thin crystalline cap-layer, creating a crystalline-amorphous hybrid coating, enabling optimised coating designs with a number of advantages for both scientific and industrial applications.Using an appropriate crystalline top-layer can allow a significant fraction of the incoming light to be reflected by the top layer along, reducing the laser power present in the multi-layer stack below. This reduced power can in turn change the requirements for the coating materials which can be used in the stack, for example allowing the use of materials with a high optical absorption which would be intolerant to higher light power. This has direct applications in gravitational wave detectors, where minimising the absorption of light in the coatings is essential to allow future mirrors to operated at cryogenic temperatures. There are also many potential applications in industry, where coatings which are tolerant of high light intensity are required in situations where high laser powers, or very small laser beams, are required.

光学涂层通常由交替的非晶（玻璃状）材料的多个薄层组成，广泛用于形成高反射镜、高效的抗反射涂层或允许传输特定波长的滤光片。高反射涂层是引力波探测器的关键部分。这些仪器测量引力波穿过地球时引起的微小长度变化，迄今为止已检测到近 100 个来自黑洞和中子星合并的天体物理引力波信号。未来，计划使用更灵敏的探测器来扩展引力波天文学的能力，而提高光学镜涂层的性能是这些新探测器面临的关键挑战。该项目旨在将传统的多层光学镀膜与薄晶体覆盖层相结合，创建晶体-非晶混合镀膜，从而实现优化的镀膜设计，为科学和工业应用带来许多优势。使用适当的晶体顶层可以允许大部分入射光被顶层反射，从而减少下面多层堆叠中的激光功率。这种降低的功率又可以改变对可以在堆叠中使用的涂层材料的要求，例如允许使用具有高光学吸收的材料，而该材料不能耐受更高的光功率。这在引力波探测器中具有直接应用，其中最大限度地减少涂层中的光吸收对于允许未来的镜子在低温下运行至关重要。在工业中也有许多潜在的应用，在需要高激光功率或非常小的激光束的情况下，需要耐受高光强度的涂层。