학술논문
The Simons Observatory: Development and Optical Evaluation of Achromatic Half-Wave Plates
Document Type
Working Paper
Author
Sugiyama, Junna; Terasaki, Tomoki; Sakaguri, Kana; Bixler, Bryce; Sakurai, Yuki; Arnold, Kam; Crowley, Kevin T.; Datta, Rahul; Galitzki, Nicholas; Hasegawa, Masaya; Johnson, Bradley R.; Keating, Brian; Kusaka, Akito; Lee, Adrian; Matsumura, Tomotake; Mcmahon, Jeffrey; Silva-Feaver, Maximiliano; Wang, Yuhan; Yamada, Kyohei
Source
J Low Temp Phys (2024)
Subject
Language
Abstract
The Simons Observatory (SO) experiment is a cosmic microwave background (CMB) experiment located in the Atacama Desert, Chile. The SO' s small aperture telescopes (SATs) consist of three telescopes designed for precise CMB polarimetry at large angular scales. Each SAT uses a cryogenic rotating half-wave plate (HWP) as a polarization modulator to mitigate atmospheric 1/f noise and other systematics. To realize efficient polarization modulation over the observation bands, we fabricated an achromatic HWP (AHWP) consisting of three sapphire plates with anti-reflection coatings. The AHWP is designed to have broadband modulation efficiency and transmittance. This paper reports on the design and the preliminary characterization of the AHWPs for SATs.