title: Polarization multiplexed 16QAM transmission employing modified digital back-propagation.
abstract: We experimentally demonstrate performance enhancements enabled by weighted digital back propagation method for 28 Gbaud PM-16QAM transmission systems, over a 250 km ultra-large area fibre, using only one back-propagation step for the entire link, enabling up to 3 dB improvement in power tolerance with respect to linear compensation only. We observe that this is roughly the same improvement that can be obtained with the conventional, computationally heavy, non-weighted digital back propagation compensation with one step per span. As a further benchmark, we analyze performance improvement as a function of number of steps, and show that the performance improvement saturates at approximately 20 steps per span, at which a 5 dB improvement in power tolerance is obtained with respect to linear compensation only. Furthermore, we show that coarse-step self-phase modulation compensation is inefficient in wavelength division multiplexed transmission.
authors.affiliation: Photonics Systems Group, Tyndall National Institute and Department of Electrical Engineering/Physics, University College Cork, Dyke Parade, Prospect Row, Cork, Ireland. danish.rafique@tyndall.ie
authors.forename: Danish
authors.initials: D
authors.lastname: Rafique
authors.forename: Marco
authors.initials: M
authors.lastname: Mussolin
authors.forename: Jonas
authors.initials: J
authors.lastname: Mårtensson
authors.forename: Marco
authors.initials: M
authors.lastname: Forzati
authors.forename: Johannes K
authors.initials: JK
authors.lastname: Fischer
authors.forename: Lutz
authors.initials: L
authors.lastname: Molle
authors.forename: Markus
authors.initials: M
authors.lastname: Nölle
authors.forename: Colja
authors.initials: C
authors.lastname: Schubert
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Ellis