TY - CONF
T1 - Prototype demonstration of the broadband anti-reflection coating on sapphire using a sub-wavelength structure
AU - Matsumura, T.
AU - Takaku, R.
AU - Hanany, S.
AU - Imada, H.
AU - Ishino, H.
AU - Katayama, N.
AU - Kobayashi, Y.
AU - Komatsu, K.
AU - Konishi, K.
AU - Kuwata-Gonokami, M.
AU - Nakamura, S.
AU - Sakurai, H.
AU - Sakurai, Y.
AU - Wen, Q.
AU - Young, K.
AU - Yumoto, J.
N1 - Funding Information:
ACKNOWLEDGMENT This work was supported by JSPS KAKENHI Grant Number 15H05441, 17H01125, 17K14272. This work was also supported by JSPS Core-to-Core Program, A. This work was also supported by World Premier International Research Center Initiative (WPI), MEXT, Japan.
Funding Information:
This work was supported by JSPS KAKENHI Grant Number 15H05441, 17H01125, 17K14272. This work was also supported by JSPS Core-to-Core Program, A. This work was also supported by World Premier International Research Center Initiative (WPI), MEXT, Japan.
Publisher Copyright:
© 2018 29th IEEE International Symposium on Space Terahertz Technology, ISSTT 2018.All Rights Reserved.
PY - 2018
Y1 - 2018
N2 - We report the development of the broadband antireflection (AR) coating on sapphire using a sub-wavelength structure for a cosmic microwave background (CMB) polarization experiment. One of the challenges in the CMB polarization experiment is to disentangle the sources of the polarized emission among the CMB and the galactic emissions from our Galaxy. This leads a need of a cryogenically compatible broadband AR coating on a millimeter wave optical element used in a CMB telescope. We design and fabricate the AR subwavelength structure using a laser machining on a sapphire plate, which is a commonly used material as a half-wave plate at millimeter wavelength. We fabricate a prototype sample and evaluate the transmittance of an SWS AR sapphire for the fractional bandwidth of about 1.5. We show the agreement between the measured transmittance and the prediction based on the fabricated shape. The projected transmittance based on the measurement achieves above 90% above 50 GHz. We finally discuss the room of the improvement and the applicability for this technology for a future CMB polarization experiment.
AB - We report the development of the broadband antireflection (AR) coating on sapphire using a sub-wavelength structure for a cosmic microwave background (CMB) polarization experiment. One of the challenges in the CMB polarization experiment is to disentangle the sources of the polarized emission among the CMB and the galactic emissions from our Galaxy. This leads a need of a cryogenically compatible broadband AR coating on a millimeter wave optical element used in a CMB telescope. We design and fabricate the AR subwavelength structure using a laser machining on a sapphire plate, which is a commonly used material as a half-wave plate at millimeter wavelength. We fabricate a prototype sample and evaluate the transmittance of an SWS AR sapphire for the fractional bandwidth of about 1.5. We show the agreement between the measured transmittance and the prediction based on the fabricated shape. The projected transmittance based on the measurement achieves above 90% above 50 GHz. We finally discuss the room of the improvement and the applicability for this technology for a future CMB polarization experiment.
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M3 - Paper
AN - SCOPUS:85062692870
SP - 54
EP - 60
T2 - 29th IEEE International Symposium on Space Terahertz Technology, ISSTT 2018
Y2 - 26 March 2018 through 28 March 2018
ER -