Optical performance monitoring for translucent/transparent optical networks

In-band optical signal-to-noise ratio monitoring technique based on Brillouin fiber ring laser

“…The deployment of high-speed transparent and reconfigurable optical networks requires effective flexible and robust optical performance monitoring techniques for ensuring high quality of service and high level of resiliency [1]. With the shift to advanced coherent modulation formats, high spectral efficiency optical networks can be designed with almost no restriction on accumulated chromatic dispersion (CD) and polarization mode dispersion (PMD) thanks to the use of digital signal processing at the receiver.…”

“…Therefore, real-time monitoring of the optical signal-to-noise ratio (OSNR) is a requirement in order to ensure the signal quality, monitor potential failures in the transmission link, and decide if channel regeneration is required. Indeed, when an optical channel reaches an OSNR level below a given threshold, it should undergo optical or optoelectronic regeneration [1,2] in order to increase the transmission reach.…”

Novel method for the measurement of the wavelength-resolved high-resolution polarization state of optical signals and application to the monitoring of communication signals

“…PMD is usually monitored as a dispersive effect in the second layer, i.e. isolating each channel separately, and involves a conversion to the electric domain through detection [1,2]. Nowadays, monitoring techniques for PMD can be divided in post-filtering RF analysis, eye pattern analysis and State of Polarization (SOP) evolution.…”

Joint PDL and In-band OSNR Monitoring Supported by Data-Aided Channel Estimation

“…Techniques based on polarization nulling, spectral analysis, asynchronous histograms, neural networks [1,8] and signal equalization [9] have been presented. However, these methods are not applicable to polarization-division multiplexing (PDM) with amplitude and phase modulation or have not been evaluated with combined deterministic and statistic channel impairments proving reliable estimation under realistic conditions.…”