The Simons Observatory: Overview of the Cryogenic Half-wave Plate Polarization Modulators

@misc{sugiyama2026simons,
  title = {{The Simons Observatory: Overview of the Cryogenic Half-wave Plate Polarization Modulators}},
  author = {Junna Sugiyama and Kyohei Yamada and Bryce Bixler and Daichi Sasaki and Yuki Sakurai and Kam Arnold and Nicholas Galitzki and Akito Kusaka},
  howpublished = {arXiv},
  year = {2026},
  month = jul,
  doi = {10.48550/arxiv.2607.00265},
  eprint = {2607.00265},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2607.00265},
}

TY  - UNPB
TI  - The Simons Observatory: Overview of the Cryogenic Half-wave Plate Polarization Modulators
AU  - Junna Sugiyama
AU  - Kyohei Yamada
AU  - Bryce Bixler
AU  - Daichi Sasaki
AU  - Yuki Sakurai
AU  - Kam Arnold
AU  - Nicholas Galitzki
AU  - Akito Kusaka
PY  - 2026
DA  - 2026/07/01
PB  - arXiv
DO  - 10.48550/arxiv.2607.00265
UR  - https://arxiv.org/abs/2607.00265
AB  - The Simons Observatory (SO) is a ground-based Cosmic Microwave Background (CMB) experiment that is located in the Atacama plateau. The Small Aperture Telescopes (SATs) of SO are optimized for polarimetry on the degree scale. Atmospheric 1/f contamination of the CMB signal poses a significant challenge for observations at this angular scale. In order to control the 1/f noise, the SATs utilize a Cryogenic Half-Wave Plate (CHWP) in their optics. The CHWP modulates the polarization signal to a higher frequency to separate it from the unpolarized atmospheric noise. Precision measurements of the CHWP rotation angle are required to successfully recover the target polarized signals. We present a method to reconstruct the CHWP rotation angle that achieves a noise level of 0.16 μrad√s, meeting our requirement.
ER  -