Coatings for Next Generation Gravitational Wave Interferometers

下一代引力波干涉仪涂层

• 批准号: 2110101
• 负责人: Carmen Menoni
• 金额: $ 44.99万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2110101&HistoricalAwards=false
• 关键词: Coatings; Next; Generation; Gravitational; Wave

This award supports research in relativity and relativistic astrophysics and it addresses the priority areas of NSF's "Windows on the Universe" Big Idea. The first detection of gravitational waves from the collision of two massive black holes by the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors in Livingston, Louisiana, and Hanford, Washington in 2015 not only confirmed Einstein's predictions of the existence of gravitational waves but also ratified years of efforts in the development of gravitational wave detectors (GWD). Gravitational wave detectors are interferometers in which an intense laser beam bounces between two sets of mirrors in orthogonal arms. Gravitational waves cause differences in the path length of the laser beam between the two interferometer arms, giving rise to a distinct interference pattern that when analyzed identifies the event that created them. The detection sensitivity of GWD is determined by various noise sources, among which thermal noise of the coatings in the mirrors of the interferometer is a main component. Thermal noise in the high reflectance amorphous oxide coatings in the interferometer's mirrors causes path length differences that can mask the signals from gravitational waves. To increase the sensitivity of present GWD and meet the demands of future GWD, a concerted effort to understand and control the mechanisms that give rise to thermal noise in amorphous oxide coatings is imperative. The projects will offer a diverse group of graduate students opportunities to gain in-depth understanding of the physical mechanisms that affect internal friction in amorphous materials and at the same time gain valuable expertise in optical sciences. This interdisciplinary research project will train students with valuable skills to contribute to advance science and technology in academic, national laboratory and industrial settings.The PI's team has recently achieved a breakthrough result. They have identified mixtures of titanium dioxide and germanium dioxide that show internal dissipations at a level of 0.0001. Such a low level of mechanical loss can provide for an almost a factor of two improvement on the level of Brownian noise with respect to the state-of-the-art materials. These results will make it possible to produce the mirrors that will meet the thermal noise requirements for the planned upgrades of the Advanced LIGO detectors. The team will investigate the fundamental mechanisms in TiO2 doped GeO2 that lead to such low mechanical loss and implement strategies to further reduce it. It will also investigate the optical properties of thin films to meet the stringent absorption loss requirements of the coatings for Advanced LIGO detectors. Multilayer dielectric coatings based on these optimized materials will be deposited by ion beam sputtering and characterized for their Brownian noise, which reduction greatly impacts the sensitivity of gravitational wave detectors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项支持相对论和相对论天体物理学的研究，并介绍了NSF“宇宙上的Windows”的优先领域。双激光干涉仪在路易斯安那州利文斯顿和华盛顿州汉福德的双激光干涉仪重力波观测器（Ligo）探测器和华盛顿汉福德的引力波第一次检测到两个巨大黑洞的引力波，不仅证实了爱因斯坦对重力波的存在的预测还批准了重力波探测器（GWD）发展的年份。引力波检测器是干涉仪，其中强烈的激光束在正交臂中的两组镜子之间反弹。引力波在两个干涉仪臂之间的激光束的路径长度上导致差异，从而产生独特的干扰模式，当分析时，将确定创建它们的事件。 GWD的检测灵敏度由各种噪声源确定，其中干涉仪镜子中的涂层的热噪声是主要成分。高反射率中的热噪声在干涉仪镜像中无定形氧化物涂层会导致路径长度差异，从而掩盖了引力波的信号。为了提高当前GWD的敏感性并满足未来GWD的需求，必须协同理解和控制引起无定形氧化物涂层中热噪声的机制。这些项目将为各种研究生提供了一些机会，以深入了解影响无定形材料内部摩擦的物理机制，同时获得光学科学方面的宝贵专业知识。这个跨学科研究项目将培训具有宝贵技能的学生，以在学术，国家实验室和工业环境中提高科学技术做出贡献。PI的团队最近取得了突破性的结果。 他们已经确定了二氧化钛和也显示于0.0001水平的内部耗散的混合物。 相对于最先进的材料，这种低水平的机械损失可以使布朗噪声水平的水平几乎可以提高两倍。这些结果将有可能产生镜子，以满足高级LIGO探测器计划升级的热噪声要求。 该团队将调查TIO2掺杂的GEO2中的基本机制，从而导致如此低的机械损失并实施进一步减少它的策略。 它还将研究薄膜的光学特性，以满足晚期LIGO探测器涂层的严格吸收损失要求。 基于这些优化材料的多层介电涂层将通过离子束溅射沉积并以其布朗噪声为特征，这极大地影响了引力波检测器的敏感性。该奖项反映了NSF的法定任务，并通过使用评估值得进行评估，使基金会的智力优点和更广泛的影响评论标准。