Progress and feasibility for a unified standard for frequency, time, and length

The recent successful extension of frequency synthesis upward in the infrared to the 88-THz frequency of the very stable methane frequency standard has implications for expanded uses of frequency/time metrology and hence of frequency/time dissemination systems. After further refinements of the infrared frequency synthesis techniques, metrologists will have the opportunity to define a value for the speed of light and to use a particular frequency standard --the most accurate one--as a unified standard for frequency, time, and length.

[1]  Kenneth M. Evenson,et al.  ABSOLUTE FREQUENCY MEASUREMENTS OF THE 28‐ AND 78‐μm cw WATER VAPOR LASER LINES , 1970 .

[2]  Helmut Hellwig,et al.  Areas of Promise for the Development of Future Primary Frequency Standards , 1970 .

[3]  J. Terrien,et al.  NEWS FROM THE INTERNATIONAL BUREAU OF WEIGHTS AND MEASURES: International Cooperation in Radionuclid , 1966 .

[4]  A. G. McNish.  The Basis of Our Measuring System , 1959, Proceedings of the IRE.

[5]  Allen V. Astin,et al.  Standards of Measurement , 1968 .

[6]  R. Kamper.  The Josephson effect , 1969 .

[7]  K. Evenson,et al.  Role of infrared frequency synthesis in metrology , 1972 .

[8]  Helmut Hellwig,et al.  Frequency Stability of Methane‐Stabilized He–Ne Lasers , 1972 .

[9]  F K Harris,et al.  Accurate Hamon-Pair Potentiometer for Josephson Frequency-to-Voltage Measurements , 1970 .

[10]  Z. Bay.  The Constancy of the Velocity of Light and Prospects for a Unified Standardization of Time, Frequency and Length , 1972 .

[11]  C H Townes,et al.  Production of Coherent Radiation by Atoms and Molecules. , 1965, Science.

[12]  D. Langenberg,et al.  AC Josephson Effect Determination of e/h: A Standard of Electrochemical Potential Based on Macroscopic Quantum Phase Coherence in Superconductors , 1971 .

[13]  John L. Hall,et al.  The laser absolute wavelength standard problem , 1968 .

[14]  R. L. Barger,et al.  Pressure shift and broadening of methane line at 3.39 mu studied by laser-saturated molecular absorption. , 1969 .

[15]  J. Terrien.  Scientific Metrology on the International Plane and the Bureau International des Poids et Mesures , 1965 .

[16]  Helmut Hellwig,et al.  Measurement of the Unperturbed Hydrogen Hyperfine Transition Frequency , 1970 .

[17]  D. J. Glaze,et al.  Improvements in Atomic Cesium Beam Frequency Standards at the National Bureau of Standards , 1970 .

[18]  A. Javan,et al.  Test of special relativity or of the isotropy of space by use of infrared masers. , 1964 .

[19]  K. Evenson,et al.  Extension of Absolute Frequency Measurements to the cw He–Ne Laser at 88 THz (3.39 μ) , 1972 .

[20]  L. Frenkel,et al.  Absolute frequency measurement and spectroscopy of gas laser transitions in the far infrared. , 1967 .

[21]  B. Petley.  Towards a quantum voltage standard , 1971 .