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Anti-reflection Coating for Cryogenic Silicon and Alumina Lenses in Millimeter-Wave Bands

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Abstract

A dielectric lens with high refractive index is suitable for focusing cryogenic devices in millimeter-wave bands when an appropriate anti-reflection (AR) coating is applied. Two types of AR coatings for silicon and alumina were studied at the millimeter-wave (220 GHz) band: one is by direct machining of mixed epoxy for a silicon lens array, while the other is by laser machining of an antireflective subwavelength structure for a large alumina lens used in a re-imaging optics system. The millimeter-wave optical properties of silicon, alumina, aluminum nitride, and Stycast epoxies were measured with a Fourier Transform Spectrometer (FTS) at cryogenic temperatures. The measured refractive index of the AR coating with a mixture of Stycast 1266 (n = 1.68) and Stycast 2850FTJ (n = 2.2) for silicon at 30 K was 1.84. The thickness of the epoxy AR coating was precisely controlled with direct machining. Transmittance of the AR-coated silicon substrate, measured with FTS, was approximately 95 % at the center frequency of the 220 GHz band with a bandwidth of 25 % at 27 K. An antireflective subwavelength structure was designed for an alumina sample with periodic cylindrical holes. The measured 220-GHz-band transmittance was above 90 % with a bandwidth of 25 % at 25 K.

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References

  1. P.K. Day et al., Nature 425, 817–821 (2003)

    Article  ADS  Google Scholar 

  2. K.D. Irwin et al., Appl. Phys. Lett. 69, 1945–1947 (1996)

    Article  ADS  Google Scholar 

  3. A. Baryshev et al., IEEE Trans. THz Sci. Technol. 1, 112–123 (2011)

    Article  Google Scholar 

  4. J.W. Fowler et al., Appl. Opt. 46, 3444–3454 (2007)

    Article  ADS  Google Scholar 

  5. T. Tomaru et al., Proc. SPIE 8452, 84521H (2012)

    Article  Google Scholar 

  6. T. Nitta et al., IEEE Trans. THz Sci. Technol. 3, 56–62 (2013)

    Article  Google Scholar 

  7. A. Suzuki et al., Proc. SPIE. 8452, 84523H (2012)

    Article  Google Scholar 

  8. J. Lau et al., Appl. Opt. 45, 3746–3751 (2006)

    Article  ADS  Google Scholar 

  9. A.J. Gatesman et al., IEEE Microw. Guided Wave Lett. 10, 264–266 (2000)

    Article  Google Scholar 

  10. H.-W. Hübers et al., Infrared Phys. Technol. 42, 41–47 (2001)

    Article  ADS  Google Scholar 

  11. T. Kamizuka et al., Proc. SPIE. 8450, 845051 (2012)

    Article  Google Scholar 

  12. H. Matsuo et al., Publ. Astron. Soc. Japan 50, 359–366 (1998)

    Article  ADS  Google Scholar 

  13. E.V. Loewenstein, D.R. Smith, Appl. Opt. 10, 577–583 (1971)

    Article  ADS  Google Scholar 

  14. E.V. Loewenstein et al., Appl. Opt. 12, 398–406 (1973)

    Article  ADS  Google Scholar 

  15. M. Barucci et al., Cryogenics 39, 963–966 (1999)

    Article  ADS  Google Scholar 

  16. D.H. Raguin, G.M. Morris, Appl. Opt. 32, 1154–1167 (1993)

    Article  ADS  Google Scholar 

Download references

Acknowledgments

The authors would like to thank A. Suzuki (U.C. Berkeley) and T. Matsumura, Y. Inoue (KEK) for useful discussions. This work was supported by MEXT/JSPS KAKENHI Grant Number 21111003, 21244023, 25247022, 24111712.

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Authors and Affiliations

  1. Institute of Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan

    Tom Nitta, Masumichi Seta & Naomasa Nakai

  2. Department of Astronomy, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan

    Shigeyuki Sekiguchi & Masakazu Sekine

  3. Advanced Technology Center, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588, Japan

    Yutaro Sekimoto, Kenji Mitsui, Norio Okada, Kenichi Karatsu, Hiroshi Matsuo & Takashi Noguchi

  4. Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan

    Masato Naruse

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  1. Tom Nitta
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  2. Shigeyuki Sekiguchi
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Correspondence to Tom Nitta.

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Nitta, T., Sekiguchi, S., Sekimoto, Y. et al. Anti-reflection Coating for Cryogenic Silicon and Alumina Lenses in Millimeter-Wave Bands. J Low Temp Phys 176, 677–683 (2014). https://doi.org/10.1007/s10909-013-1059-3

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  • DOI: https://doi.org/10.1007/s10909-013-1059-3

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