TY - JOUR
T1 - Performance of a 200 mm Diameter Achromatic HWP with Laser-Ablated Sub-Wavelength Structures
AU - for the LiteBIRD collaboration
AU - Takaku, R.
AU - Ghigna, T.
AU - Hanany, S.
AU - Hoshino, Y.
AU - Ishino, H.
AU - Katayama, N.
AU - Komatsu, K.
AU - Konishi, K.
AU - Kuwata-Gonokami, M.
AU - Matsumura, T.
AU - Sakurai, H.
AU - Sakurai, Y.
AU - Wen, Q.
AU - Yamasaki, N. Y.
AU - Yumoto, J.
N1 - Funding Information:
We acknowledge the World Premier International Research Center Initiative (WPI), MEXT, Japan for support through Kavli IPMU. This work was supported by JSPS KAKENHI Grant Numbers JP17H01125, 19K14732, 18J20148, 18KK0083, and JSPS Core-to-Core Program, A. Advanced Research Networks. This work was also supported by the New Energy and Industrial Technology Development Organization (NEDO) project “Development of advanced laser processing with intelligence based on high-brightness and high efficiency laser technologies” by Council for Science, Technology and Innovation (CSTI), Cross-ministerial Strategic Innovation Promotion Program (SIP), “Photonics and Quantum Technology for Society 5.0” and by the Center of Innovation Program, from Japan Science and Technology Agency, JST. LiteBIRD (phase A) activities are supported by the following funding sources: ISAS/JAXA, MEXT, JSPS, KEK (Japan); CSA (Canada); CNES, CNRS, CEA (France); DFG (Germany); ASI, INFN, INAF (Italy); RCN (Norway); AEI (Spain); SNSA, SRC (Sweden); NASA, DOE (USA).
Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2022
Y1 - 2022
N2 - We laser-ablated sub-wavelength structures (SWS) on 200 mm diameter birefringent sapphire disks to produce broadband anti-reflection coating (ARC). The disks were assembled into a stack of five plates making an achromatic half-wave plate (AHWP) suitable for operation between 40 and 140 GHz. We report on the SWS fabrication and transmission measurements of the stack at room temperature. From the measurements, we compute a band average transmission and modulation efficiency for nine spectral bands that correspond to the frequency coverage of the LiteBIRD Low-Frequency Telescope (LFT). We also assess the level of instrumental polarization the AHWP exhibits. We discuss paths for further development to minimize the instrumental polarization from the AHWP. This work is a development milestone toward the implementation of an AHWP for the LiteBIRD satellite.
AB - We laser-ablated sub-wavelength structures (SWS) on 200 mm diameter birefringent sapphire disks to produce broadband anti-reflection coating (ARC). The disks were assembled into a stack of five plates making an achromatic half-wave plate (AHWP) suitable for operation between 40 and 140 GHz. We report on the SWS fabrication and transmission measurements of the stack at room temperature. From the measurements, we compute a band average transmission and modulation efficiency for nine spectral bands that correspond to the frequency coverage of the LiteBIRD Low-Frequency Telescope (LFT). We also assess the level of instrumental polarization the AHWP exhibits. We discuss paths for further development to minimize the instrumental polarization from the AHWP. This work is a development milestone toward the implementation of an AHWP for the LiteBIRD satellite.
KW - Broadband achromatic half-wave plate
KW - Broadband anti-reflection
KW - Cosmic microwave background
KW - Laser machining
KW - Millimeter-wave instruments
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U2 - 10.1007/s10909-022-02922-6
DO - 10.1007/s10909-022-02922-6
M3 - Article
AN - SCOPUS:85140719725
SN - 0022-2291
JO - Journal of Low Temperature Physics
JF - Journal of Low Temperature Physics
ER -