A system for measuring absolute frequencies of up to 4.25 THz using a Josephson point contact

  • Yukinobu Mild
  • Atsushi Onae
  • Tomizo Kurosawa
  • Eiichi Sakuma


A system for measuring the absolute frequency of a far-infrared (FIR) laser is described. Josephson point contacts have been utilized in the system as a frequency harmonic mixer connecting microwaves and optically pumped CH3OH laser lines. The Josephson point contacts are capable of generating beat signals of 90 GHz microwaves and FIR waves of up to 4.25 THz. To measure the frequency of the beat signals from the Josephson junction with a frequency counter, tracking oscillators have been developed, which tracks the beat signals by phase locking and regenerate clean signals for frequency counting. It is shown that the absolute frequency can be measured to an accuracy of about 100 Hz by using the tracking oscillators.


Microwave CH3OH Point Contact Absolute Frequency Clean Signal 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1).
    C. O. Weiss, Appl. Phys. B Vol 34 (1984) 63.Google Scholar
  2. 2).
    D. G. McDonald, A. S. Risley, J. D. Cupp, K. M. Evenson, and J. R. Ashley, Appl. Phys. Lett., Vol. 20 (1972) 296.Google Scholar
  3. 3).
    T. G. Blaney, N. R. Cross, D. J. E. Knight, G. J. Edwards, and P. R. Pearce, J. Phys. D: Appl. Phys., Vol. 13 (1980) 1365.Google Scholar
  4. 4).
    Y. Miki, E. Sakuma, and M. Morimura, IEEE Trans. Instrum. Meas., Vol. IM-36 (1987) 630.Google Scholar
  5. 5).
    Y. Miki and E. Sakuma, Jpn. J. Appl. Phys., Vol. 26 (1987) L1482.Google Scholar
  6. 6).
    H. Yan, T. Kurosawa, A. Onae, and E. Sakuma, Opt. Commun., Vol.73 (1989) 136.Google Scholar
  7. 7).
    A. Onae, T. Kurosawa, Y. Miki, and E. Sakuma, Opt. Commun., Vol. 88(1992) 110.Google Scholar
  8. 8).
    B. Dahmani and A. Clairon, Int. J. Infrared Mill. Waves, Vol. 5 (1984) 1053.Google Scholar
  9. 9).
    Y. Miki and E. Sakuma, Int. J. Infrared Mill. Waves, Vol. 6 (1985) 599.Google Scholar
  10. 10).
    L. M. Matarrese and K. M. Evenson, Appl. Phys. Lett., Vol. 17 (1970) 8.Google Scholar
  11. 11).
    D. A. Weitz, W. J. Skocpol, and M. Tinkham, J. Appl. Phys., Vol. 49 (1978) 4873.Google Scholar
  12. 12).
    F. M. Gardner, Phaselock Techniques, John Wiley & Sons, New York, 1979.Google Scholar
  13. 13).
    W. P. Robins, Phase Noise in Signal Sources, Peter Peregrinus Ltd., London, 1982.Google Scholar

Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • Yukinobu Mild
    • 1
  • Atsushi Onae
    • 1
  • Tomizo Kurosawa
    • 1
  • Eiichi Sakuma
    • 1
  1. 1.National Research Laboratory of MetrologyIbarakiJapan

Personalised recommendations