Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Generation of Ultrastable microwaves via optical frequency division



Tara M. Fortier, Matthew S. Kirchner, Jennifer A. Taylor, James C. Bergquist, Yanyi Jiang, Andrew D. Ludlow, Christopher W. Oates, Till P. Rosenband, Scott A. Diddams, Franklyn J. Quinlan, Nathan D. Lemke


A frequency-stabilized femtosecond laser optical frequency comb serves as a source of microwave signals having very low close-to-carrier phase noise. Comparison of two independent systems shows combined absolute phase noise of -100 dBc/Hz at an offset of 1 Hz from the 10 GHz carrier. The corresponding timing jitter is 2 fs, integrated from 1 Hz to 1 MHz.
Nature Photonics


frequency comb, phase noise, microwave synthesis
Created June 26, 2011, Updated February 19, 2017