Title :
Frequency measurement of a CH4 hyperfine line at 88 THz/`optical clock´
Author :
Weiss, C.O. ; Kramer, G. ; Lipphardt, B. ; Garcia, E.
Author_Institution :
Physikalisch-Technishe Bundesanstalt, Braunschweig, West Germany
fDate :
10/1/1988 12:00:00 AM
Abstract :
A frequency-measurement chain was used to measure the frequency of a hyperfine line of the ν3P(7) CH4 multiplet, which was resolved by a linear optical Ramsey resonance technique. A frequency of 88, 376, 181, 599.7±1 kHz is found. The Ramsey experiment was used as a clock; to ~100 s the stability of this optical clock is equal to a high-performance commercial Cs clock. It is concluded that the frequency division necessary for optical transitions to be used as a clock does not necessarily introduce the noise and errors which would a priori rule out optical transitions as candidates for good clocks
Keywords :
errors; frequency measurement; infrared spectra of organic molecules and substances; molecular hyperfine structure; noise; organic compounds; visible spectra of organic molecules and substances; 181 THz; 376 THz; 599.7 THz; 88 THz; Cs clock; errors; frequency division; frequency-measurement chain; hyperfine line; linear optical Ramsey resonance technique; methane; multiplet; noise; optical clock; optical transitions; Clocks; Frequency conversion; Frequency measurement; Frequency synthesizers; Optical frequency conversion; Optical resonators; Oscillators; Phase noise; Pump lasers; Schottky diodes;
Journal_Title :
Quantum Electronics, IEEE Journal of
