title: Practical and cost-effective high-fidelity optical carrier dissemination using coherent communication techniques.
abstract: We report a unidirectional frequency dissemination scheme for high-fidelity optical carriers deployable over telecommunication networks. For the first time, a 10 Gb/s Binary Phase Shift Keying (BPSK) signal from an ultra-narrow linewidth laser was transmitted through a field-installed optical fibre with round-trip length of 124 km between Cork City and town of Clonakilty, without inline optical amplification. At the receiver, using coherent communication techniques and optical injection-locking the carrier was recovered with noise suppression. The beat signal between the original carrier at the transmitter and recovered carrier at the receiver shows a linewidth of 2.8 kHz. Long term stability measurements revealed fractional instabilities (True Allan deviation) of 3.3 × 10(-14) for 1 s averaging time, prior to phase noise cancellation.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Sooudi
authors.forename: James
authors.initials: J
authors.lastname: O'Gorman
authors.forename: Paul
authors.initials: P
authors.lastname: Gunning
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Ellis
authors.forename: Fatima C Garcia
authors.initials: FC
authors.lastname: Gunning
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Manning