title: Optical injection locking-based amplification in phase-coherent transfer of optical frequencies.
abstract: We demonstrate the use of an optical injection phase locked loop (OIPLL) as a regenerative amplifier for optical frequency transfer applications. The optical injection locking provides high gain within a narrow bandwidth (<100  MHz) and is capable of preserving the fractional frequency stability of the incoming carrier to better than 10(-18) at 1000 s. The OIPLL was tested in the field as a mid-span amplifier for the transfer of an ultrastable optical carrier, stabilized to an optical frequency standard, over a 292 km long installed dark fiber link. The transferred frequency at the remote end reached a fractional frequency instability of less than 1×10(-19) at averaging time of 3200 s.
authors.forename: Joonyoung
authors.initials: J
authors.lastname: Kim
authors.forename: Harald
authors.initials: H
authors.lastname: Schnatz
authors.forename: David S
authors.initials: DS
authors.lastname: Wu
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Marra
authors.forename: David J
authors.initials: DJ
authors.lastname: Richardson
authors.forename: Radan
authors.initials: R
authors.lastname: Slavík