title: Coherent optical phase transfer over a 32-km fiber with 1 s instability at 10{-17}.
abstract: The phase coherence of an ultrastable optical frequency reference is fully maintained over actively stabilized fiber networks of lengths exceeding 30 km. For a 7-km link installed in an urban environment, the transfer instability is 6 x 10{-18} at 1 s. The excess phase noise of 0.15 rad, integrated from 8 mHz to 25 MHz, yields a total timing jitter of 0.085 fs. A 32-km link achieves similar performance. Using frequency combs at each end of the coherent-transfer fiber link, a heterodyne beat between two independent ultrastable lasers, separated by 3.5 km and 163 THz, achieves a 1-Hz linewidth.
authors.affiliation: JILA, National Institute of Standards and Technology and University of Colorado Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA.
authors.forename: Seth M
authors.initials: SM
authors.lastname: Foreman
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Ludlow
authors.forename: Marcio H G
authors.initials: MH
authors.lastname: de Miranda
authors.forename: Jason E
authors.initials: JE
authors.lastname: Stalnaker
authors.forename: Scott A
authors.initials: SA
authors.lastname: Diddams
authors.forename: Jun
authors.initials: J
authors.lastname: Ye