| Autor: |
Nadolski A, Vieira JD, Sobrin JA, Kofman AM, Ade PAR, Ahmed Z, Anderson AJ, Avva JS, Basu Thakur R, Bender AN, Benson BA, Bryant L, Carlstrom JE, Carter FW, Cecil TW, Chang CL, Cheshire JR, Chesmore GE, Cliche JF, Cukierman A, de Haan T, Dierickx M, Ding J, Dutcher D, Everett W, Farwick J, Ferguson KR, Florez L, Foster A, Fu J, Gallicchio J, Gambrel AE, Gardner RW, Groh JC, Guns S, Guyser R, Halverson NW, Harke-Hosemann AH, Harrington NL, Harris RJ, Henning JW, Holzapfel WL, Howe D, Huang N, Irwin KD, Jeong O, Jonas M, Jones A, Korman M, Kovac J, Kubik DL, Kuhlmann S, Kuo CL, Lee AT, Lowitz AE, McMahon J, Meier J, Meyer SS, Michalik D, Montgomery J, Natoli T, Nguyen H, Noble GI, Novosad V, Padin S, Pan Z, Paschos P, Pearson J, Posada CM, Quan W, Rahlin A, Riebel D, Ruhl JE, Sayre JT, Shirokoff E, Smecher G, Stark AA, Stephen J, Story KT, Suzuki A, Tandoi C, Thompson KL, Tucker C, Vanderlinde K, Wang G, Whitehorn N, Yefremenko V, Yoon KW, Young MR |
| Jazyk: |
angličtina |
| Zdroj: |
Applied optics [Appl Opt] 2020 Apr 01; Vol. 59 (10), pp. 3285-3295. |
| DOI: |
10.1364/AO.383921 |
| Abstrakt: |
We present two prescriptions for broadband ($ {\sim} 77 - 252\;{\rm GHz} $), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements-in our case, 5 mm diameter half-spheres (called "lenslets"). The coatings comprise three layers of commercially available, polytetrafluoroethylene-based, dielectric sheet material. The lenslet coating is molded to fit the 150 mm diameter arrays directly, while the large-diameter lenses are coated using a tiled approach. We review the fabrication processes for both prescriptions, then discuss laboratory measurements of their transmittance and reflectance. In addition, we present the inferred refractive indices and loss tangents for the coating materials and the aluminum oxide substrate. We find that at 150 GHz and 300 K the large-format coating sample achieves $ (97 \pm 2)\% $ transmittance, and the lenslet coating sample achieves $ (94 \pm 3)\% $ transmittance. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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