Stabilization of femtosecond laser frequency combs with subhertz residual linewidths.
We demonstrate that femtosecond laser frequency combs (FLFCs) can have a subhertz linewidth across their entire emission spectra when they are phase locked to a reference laser with a similarly narrow linewidth. Correspondingly, the coherence time of the comb components relative to the reference laser can be of the order of a few seconds. Thus we are able to detect high-contrast spectral interferograms at up to 10-s integration time between two FLFCs locked to a common optical reference.
Bartels
A
A
Time and Frequency Division, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA. albrecht@boulder.nist.gov
Oates
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CW
Hollberg
L
L
Diddams
S A
SA