Progress with a Determination of the Speed of Light

II. Techniques for High-accuracy Frequency Measurement in the Far Infra-red
  • T. G. Blaney
  • C. C. Bradley
  • G. J. Edwards
  • D. J. E. Knight
Conference paper


The scheme for measuring the CO2 laser frequency (shown in the Introduction) consists of three separate frequency-mixing experiments using two lower-frequency lasers as transfer oscillators. If an accurate measurement on a stabilized CO2 laser (1) is required, either all the experiments must be performed together, within the thermal drift limitations of the transfer oscillators, or the transfer oscillators must be stabilized too. Although having achieved about 1 in 107 stabilization of the HCN laser (2) we favour simultaneous frequency measurement using automated techniques, but achieving this is highly dependent on the fragile frequency-mixing diodes.


Phase Noise Laser Frequency Josephson Junction National Physical LaboratorY Microwave Oscillator 
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.
    FREED, C. and JAVAN, A., Appl. Phys. Lett., 17, 53–6 (1970).ADSCrossRefGoogle Scholar
  2. 2.
    BRADLEY, C.C., KNIGHT, D.J.E. and McGEE, C.R., Electronics Lett., 7, 381–2 (1971).Google Scholar
  3. 3.
    McDONALD, D.G., RISLEY, A.S., CUPP, J.D. and EVENSON, K.M., Appl. Phys. Lett., 18, 162–4 (1971).Google Scholar
  4. 4.
    BLANEY, T.G., BRADLEY, C.C., EDWARDS, G.J. and KNIGHT, D.J.E., Phys. Lett., 36A, 285 (1971).Google Scholar
  5. 5.
    KNIGHT, D.J.E., J. Opto-electronics, 1, 161–4 (1969).CrossRefGoogle Scholar
  6. 6.
    KNIGHT, D.J.E., Electronics Lett., 7, 383–4 (1971).CrossRefGoogle Scholar
  7. 7.
    FRENKEL, L. and SULLIVAN, T., Trans. IEEE, MTT-17, 281–2 (1969).Google Scholar
  8. 8.
    CUPP, R.E., CORCORAN, V.J. and GALLAGHER, J.J., IEEE J. Quant. Electron., QE-6, 241–3 (1970).Google Scholar
  9. 9.
    BLANEY, T.G., J. Phys. E., in the press.Google Scholar

Copyright information

© Plenum Publishing Company Ltd 1972

Authors and Affiliations

  • T. G. Blaney
    • 1
  • C. C. Bradley
    • 1
  • G. J. Edwards
    • 2
  • D. J. E. Knight
    • 2
  1. 1.Division of Electrical ScienceNational Physical LaboratoryTeddingtonEngland
  2. 2.Division of Quantum MetrologyNational Physical LaboratoryTeddingtonEngland

Personalised recommendations