title: Differential carrier phase recovery for QPSK optical coherent systems with integrated tunable lasers.
abstract: The performance of a differential carrier phase recovery algorithm is investigated for the quadrature phase shift keying (QPSK) modulation format with an integrated tunable laser. The phase noise of the widely-tunable laser measured using a digital coherent receiver is shown to exhibit significant drift compared to a standard distributed feedback (DFB) laser due to enhanced low frequency noise component. The simulated performance of the differential algorithm is compared to the Viterbi-Viterbi phase estimation at different baud rates using the measured phase noise for the integrated tunable laser.
authors.affiliation: National Physical Laboratory, Teddington, Middlesex, TW11 0LW, UK.
authors.forename: Irshaad
authors.initials: I
authors.lastname: Fatadin
authors.forename: David
authors.initials: D
authors.lastname: Ives
authors.forename: Seb J
authors.initials: SJ
authors.lastname: Savory
mesh_terms: D000465:Algorithms; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D055096:Optical Devices; D012031:Refractometry / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D018511:Systems Integration; D013685:Telecommunications / Q000295:instrumentation*