Broadband anti-reflective coatings for cosmic microwave background experiments
Broadband anti-reflective coatings for cosmic microwave background experiments
复制标题
用于宇宙微波背景实验的宽带抗反射涂层
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
M. Young
中科院分区：
文献类型：
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作者：
A. Nadolski;A. Kofman;J. Vieira;P. Ade;Z. Ahmed;A. Anderson;J. Avva;R. Thakur;A. Bender;A. Bender;B. Benson;J. Carlstrom;J. Carlstrom;F. Carter;F. Carter;T. Cecil;C. Chang;C. Chang;J. Cliche;A. Cukierman;T. Haan;J. Ding;M. Dobbs;M. Dobbs;D. Dutcher;D. Dutcher;W. Everett;A. Foster;J. Fu;J. Gallichio;J. Gallichio;A. Gilbert;J. Groh;S. Guns;R. Guyser;N. Halverson;A. Harke;A. Harke;N. Harrington;J. Henning;W. Holzapfel;N. Huang;K. Irwin;O. Jeong;M. Jonas;A. Jones;T. Khaire;M. Korman;D. Kubik;S. Kuhlmann;C. Kuo;Adrian T. Lee;Adrian T. Lee;A. Lowitz;S. Meyer;D. Michalik;J. Montgomery;T. Natoli;H. Nguyen;G. Noble;V. Novosad;S. Padin;Z. Pan;J. Pearson;C. Posada;W. Quan;A. Rahlin;J. Ruhl;J. Sayre;E. Shirokoff;E. Shirokoff;G. Smecher;J. Sobrin;A. Stark;K. Story;A. Suzuki;K. Thompson;C. Tucker;K. Vanderlinde;Gensheng Wang;N. Whitehorn;N. Whitehorn;V. Yefremenko;K. Yoon;M. Young
对更高灵敏度的需求驱使地面宇宙微波背景（CMB）实验采用更大的焦平面，这反过来又需要更大的再成像光学器件。这些光学器件的最大尺寸的实际限制促使准光耦合（小透镜耦合）、多色检测器的发展。与波导耦合探测器相比，这些探测器可以在更宽的带宽上灵敏。然而，带宽的增加是有代价的：这些系统中使用的透镜（直径高达约700 mm）和小透镜（直径约5 mm，焦平面上的半球形透镜）由高折射率材料（如硅或非晶氧化铝）制成，反射近三分之一的入射辐射。为了最大化到达探测器的微弱CMB信号，透镜和小透镜必须涂有抗反射（AR）材料。抗反射涂层必须最大限度地提高科学感兴趣波段的辐射透射率，并保持低温稳定。这种涂层是为南极望远镜（SPT）实验的第三代相机SPT-3G开发的，但开发中使用的材料和技术通常用于毫米波光学的AR涂层。基于聚四氟乙烯的三层AR涂层是宽带的，廉价的，并且可以用简单的工具制造。涂层经过现场测试; AR涂层焦平面元件于2016-2017年夏季部署，AR涂层重成像光学元件于2017-2018年部署。
The desire for higher sensitivity has driven ground-based cosmic microwave background (CMB) experiments to employ ever larger focal planes, which in turn require larger reimaging optics. Practical limits to the maximum size of these optics motivates the development of quasi-optically-coupled (lenslet-coupled), multi-chroic detectors. These detectors can be sensitive across a broader bandwidth compared to waveguide-coupled detectors. However, the increase in bandwidth comes at a cost: the lenses (up to ~700 mm diameter) and lenslets (~5 mm diameter, hemispherical lenses on the focal plane) used in these systems are made from high-refractive-index materials (such as silicon or amorphous aluminum oxide) that reflect nearly a third of the incident radiation. In order to maximize the faint CMB signal that reaches the detectors, the lenses and lenslets must be coated with an anti-reflective (AR) material. The AR coating must maximize radiation transmission in scientifically interesting bands and be cryogenically stable. Such a coating was developed for the third generation camera, SPT-3G, of the South Pole Telescope (SPT) experiment, but the materials and techniques used in the development are general to AR coatings for mm-wave optics. The three-layer polytetra uoroethylene-based AR coating is broadband, inexpensive, and can be manufactured with simple tools. The coating is field tested; AR coated focal plane elements were deployed in the 2016-2017 austral summer and AR coated reimaging optics were deployed in 2017-2018.
DOI：
10.2172/1352047
发表时间：
2016-10
期刊：
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影响因子：
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作者：
K. Abazajian;Peter Adshead;Z. Ahmed;S. Allen;D. Alonso;K. Arnold;C. Baccigalupi;J. Bartlett;
通讯作者：
K. Abazajian;Peter Adshead;Z. Ahmed;S. Allen;D. Alonso;K. Arnold;C. Baccigalupi;J. Bartlett;