Abstract
Controlling stray light at millimeter wavelengths requires special optical design and selection of absorptive materials that should be compatible with cryogenic operating environments. While a wide selection of absorptive materials exists, these typically exhibit high indices of refraction and reflect/scatter a significant fraction of light before absorption. For many lower index materials such as commercial microwave absorbers, their applications in cryogenic environments are challenging. In this paper, we present a new tool to control stray light: metamaterial microwave absorber tiles. These tiles comprise an outer metamaterial layer that approximates a lossy gradient index anti-reflection coating. They are fabricated via injection molding commercially available carbon-loaded polyurethane (25% by mass). The injection molding technology enables mass production at low cost. The design of these tiles is presented, along with thermal tests to 1 K. Room temperature optical measurements verify their control of reflectance to less than 1% up to ${{65}^ \circ}$ angles of incidence, and control of wide angle scattering below 0.01%. The dielectric properties of the bulk carbon-loaded material used in the tiles is also measured at different temperatures, confirming that the material maintains similar dielectric properties down to 3 K.
© 2021 Optical Society of America
Full Article | PDF ArticleMore Like This
Jon E. Gudmundsson, Patricio A. Gallardo, Roberto Puddu, Simon R. Dicker, Alexandre E. Adler, Aamir M. Ali, Andrew Bazarko, Grace E. Chesmore, Gabriele Coppi, Nicholas F. Cothard, Nadia Dachlythra, Mark Devlin, Rolando Dünner, Giulio Fabbian, Nicholas Galitzki, Joseph E. Golec, Shuay-Pwu Patty Ho, Peter C. Hargrave, Anna M. Kofman, Adrian T. Lee, Michele Limon, Frederick T. Matsuda, Philip D. Mauskopf, Kavilan Moodley, Federico Nati, Michael D. Niemack, John Orlowski-Scherer, Lyman A. Page, Bruce Partridge, Giuseppe Puglisi, et al.
Appl. Opt. 60(4) 823-837 (2021)
Joseph E. Golec, Shreya Sutariya, Rebecca Jackson, Jerry Zimmerman, Simon R. Dicker, Jeffrey Iuliano, Jeff McMahon, Giuseppe Puglisi, Carole Tucker, and Edward J. Wollack
Appl. Opt. 61(30) 8904-8911 (2022)
Giampaolo Pisano, Christopher Dunscombe, Peter Hargrave, Alexey Shitvov, and Carole Tucker
Appl. Opt. 62(9) 2317-2328 (2023)