Development and manufacture of laser mirror coatings for future gravitational wave observatories and other space applications

为了真正开发引力波天文学的新领域，需要进一步提高引力波探测器的灵敏度。最具挑战性的领域之一是减少与干涉检测系统中使用的激光反射镜涂层相关的热驱动运动(布朗热噪声)。斯特拉斯克莱德大学和苏格兰国家制造研究所(NMI)建立了新型ECR(电子回旋共振)离子束沉积，此外还获得了行业最佳的射频(RF)离子沉积技术。该项目将寻求研究射频和ECR离子束系统。尤其令人感兴趣的是研究使用新型氧化物混合物来增强用于超窄线宽腔的多层反射镜涂层的光学和机械性能。除此之外，基于最近在其他地方和LIGO科学合作(LSC)(包括Strathclyde和其他英国小组)内进行的研究，该项目将研究新的热处理方法，以消除(通过扩散)这些涂层中被困的惰性气体。现已知，制造过程中所需的陷阱气体除了会在所需的高温退火过程中引起气体聚集外，还会导致激光损伤敏感性增加，从而导致起泡和应力诱导的损伤。

Future improvements to gravitational wave detector sensitivities are required to truly exploit the new field of gravitational wave astronomy. One of the most challenging areas is reducing thermally driven motion (Brownian thermal noise) associated with the laser mirror coatings used in the interferometric detection system. The University of Strathclyde and the National Manufacturing Institute Scotland (NMIS) have established novel ECR (electron cyclotron resonance) ion beam deposition, in addition to procuring the industry-best RF (radio frequency) ion deposition technology. This project will seek to study both RF and ECR ion beam systems. Of particular interest is studying the use of novel oxide mixtures to enable enhanced optical and mechanical properties of multi-layer mirror coatings for use in ultra-narrow linewidth cavities. Beyond this, based on recent research carried out elsewhere and within the LIGO Scientific Collaboration (LSC) (which includes Strathclyde and other UK groups), the project will investigate novel annealing approaches for removing (by diffusion) the trapped inert gas within these coatings. Trapped gas, which is required in the manufacturing process, is now known to cause increased laser damage susceptibility, in addition to causing gas aggregation during the required high-temperature annealing that can cause blistering and stress-induced damage.