Testing ultrafast mode-locking at microhertz relative optical linewidth.
We report new limits on the phase coherence of the ultrafast mode-locking process in an octave-spanning Ti:sapphire comb.We find that the mode-locking mechanism correlates optical phase across a full optical octave with less than 2.5 microHZ relative linewidth. This result is at least two orders of magnitude below recent predictions for quantum-limited individual comb-mode linewidths, verifying that the mode-locking mechanism strongly correlates quantum noise across the comb spectrum.
Martin
Michael J
MJ
JILA, National Institute of Standards and Technology and University of Colorado Department of Physics, University of Colorado, Boulder, CO 80309-0440, USA. Michael.J.Martin@colorado.edu
Foreman
Seth M
SM
Schibli
T R
TR
Ye
Jun
J