Scalable, cost-effective, high-actuator-count deformable mirrors for astronomical adaptive optics

用于天文自适应光学的可扩展、经济高效、高执行器数量的可变形镜

• 批准号: 1105615
• 负责人: Thomas Bifano
• 金额: $ 89.92万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1105615&HistoricalAwards=false
• 关键词: Scalable; cost; effective; actuator; count

Over the past decade, adaptive optics (AO) has become indispensible as a means to compensate for aberrations introduced by atmospheric turbulence in large ground-based telescopes. The resulting gains in resolution are especially important for large telescopes. Indeed, because of their greater aperture, large ground-based telescopes have exceeded in narrow fields the fidelity possible with orbiting observatories and have led to exciting recent advances in the observation of exoplanets, characterization of planetary rings and atmospheres, and studies of galactic structure. The universal optical component that allows for this wavefront compensation is a deformable mirror (DM), which must operate at frequencies above 1 kHz and whose actuator count scales with the area of the telescope primary mirror. Indeed, DMs with tens of thousands of actuators are required for planned extremely large telescopes (ELTs) - those with apertures greater than ~20-m. The technology to make high-actuator density DMs with high production yield and therefore low cost does not exist today. A main objective of work planned by Dr. T. Bifano of Boston University is to develop such manufacturing technologies using a microelectromechanical systems (MEMS) approach. A critical failure mode of current large-format DMs has been the thousands of fragile electrical traces that route signals along the front surface from bonding pads located near the periphery of the module. This problem worsens rapidly as the actuator count increases, culminating in a yield of less than 1% for the latest attempts at constructing a high-count DM for the Gemini Planet Imager (GPI). Dr. Bifano's plans to circumvent this problem involve replacing the dense network of surface traces with through-wafer interconnects and bonding to a backside package. While this basic technique is not unprecedented in modern electronics manufacturing, technical challenges include the very large voltages (~250V) that must be endured by the silicon substrate to achieve the required DM stroke of ~3.5 microns. However, the payoff is large, since the availability of reliable high-actuator-count DMs would catalyze advances in promising imaging techniques such as Multi-Object AO and Extreme AO. An outcome of the proposed project will be fully functional MEMS DM prototypes with 2048 actuators, evaluated at a leading astronomical AO test bed. Funding for development high actuator count DMs for next-generation AO is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.

在过去的十年中，自适应光学元件（AO）变得不可或缺，作为补偿大型地面望远镜中大气湍流引入的畸变的一种手段。由于大型望远镜的分辨率增长尤其重要。 的确，由于它们的孔径更大，大型地面望远镜在狭窄的领域超过了绕线观测值的忠诚度，并导致了近期观察系外行星，行星环和气氛的表征以及银河系结构的研究令人兴奋。 允许此波前补偿的通用光学组件是可变形的镜像（DM），该镜子必须以1 kHz以上的频率运行，并且其执行器数量尺度与望远镜主镜的面积。 实际上，计划中的极大望远镜（ELT）需要数以万计的执行器的DM-孔径大于20 m的DM。 当今不存在生产高产量和低成本的高实用密度DMS的技术。波士顿大学T. Bifano博士计划的工作的主要目标是使用微机械系统（MEMS）方法开发此类制造技术。 当前大型DMS的关键故障模式是数千个易碎的电气轨迹，这些轨迹沿着位于模块周围附近的粘合垫路线路由沿着前表面的信号。 随着执行器数量的增加，该问题迅速恶化，最终的产量不到1％，用于为Gemini Planet Imager（GPI）构建高计数DM。 Bifano博士规避此问题的计划涉及通过通过磁带互连替换表面痕迹的密集网络，并将其粘合到背面包裹上。 尽管这种基本技术在现代电子制造业中并非空前，但技术挑战包括硅基板必须忍受的非常大的电压（〜250V），以实现所需的DM冲程〜3.5微米。 但是，收益很大，因为可靠的高实量计数DM的可用性将催化有希望的成像技术（例如多对象AO和Extreme AO）的进步。拟议项目的结果将是具有2048个执行器的功能性MEMS DM原型，并在领先的天文AO测试床上进行了评估。 NSF的天文学科学部通过其先进的技术和仪器计划提供了开发资金，用于下一代AO的高致致动力DMS为下一代AO提供。