Send to

Choose Destination
Phys Rev Lett. 2002 Feb 18;88(7):073601. Epub 2002 Feb 5.

Ultraprecise measurement of optical frequency ratios.

Author information

Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany.


We developed a novel technique for frequency measurement and synthesis, based on the operation of a femtosecond comb generator as transfer oscillator. The technique can be used to measure frequency ratios of any optical signals throughout the visible and near-infrared part of the spectrum. Relative uncertainties of 10(-18) for averaging times of 100 s are possible. Using a Nd:YAG laser in combination with a nonlinear crystal we measured the frequency ratio of the second harmonic nu(SH) at 532 nm to the fundamental nu(0) at 1064 nm, nu(SH)/nu(0) = 2.000 000 000 000 000 001x (1 +/- 7x10(-19)).

Supplemental Content

Full text links

Icon for American Physical Society
Loading ...
Support Center