Abstract
The frequency and wavelength of the methane-stabilized laser at 3.39 μm were directly measured against the respective primary standards. With infrared frequency synthesis techniques, we obtain THz. With frequency-controlled interferometry, we find μm. Multiplication yields the speed of light m/sec, in agreement with and 100 times less uncertain than the previously accepted value. The main limitation is asymmetry in the krypton 6057-Å line defining the meter.
- Received 11 September 1972
DOI:https://doi.org/10.1103/PhysRevLett.29.1346
©1972 American Physical Society