title: Demonstration of in-service wavelength division multiplexing optical-signal-to-noise ratio performance monitoring and operating guidelines for coherent data channels with different modulation formats and various baud rates.
abstract: We demonstrated a delay-line interferometer (DLI)-based, optical-signal-to-noise ratio (OSNR) monitoring scheme of 100  Gbit/s polarization multiplexed quadrature-phase-shift-keying (PM-QPSK) four-channel WDM at 50-GHz International Telecommunication Union (ITU) grid with <0.5  dB error for signals with up to 26 dB of actual OSNR. We also demonstrated data format transparency and baud rate tunability of the OSNR monitor by measuring the OSNR for a 200  Gbit/s PM-16-QAM (25-Gbaud) signal and a 200  Gbit/s PM-QPSK (50-Gbaud) signal. We also explored and studied different monitor parameters, including the shape of the filter spectrum, the bandwidth of the filter, DLI delay, and DLI phase-detuning to determine the design guidelines for a desired level of accuracy for the OSNR monitor in an optical network.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Chitgarha
authors.forename: Salman
authors.initials: S
authors.lastname: Khaleghi
authors.forename: Wajih
authors.initials: W
authors.lastname: Daab
authors.forename: Ahmed
authors.initials: A
authors.lastname: Almaiman
authors.forename: Morteza
authors.initials: M
authors.lastname: Ziyadi
authors.forename: Amirhossein
authors.initials: A
authors.lastname: Mohajerin-Ariaei
authors.forename: Devora
authors.initials: D
authors.lastname: Rogawski
authors.forename: Moshe
authors.initials: M
authors.lastname: Tur
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Touch
authors.forename: Vijay
authors.initials: V
authors.lastname: Vusirikala
authors.forename: Wendy
authors.initials: W
authors.lastname: Zhao
authors.forename: Alan E
authors.initials: AE
authors.lastname: Willner