Detailseite
Projekt Druckansicht

Faseroptische parametrische Verstärker für Signalregeneration in Übertragungssystemen mit höherwertigen Modulationsformen

Fachliche Zuordnung Elektronische Halbleiter, Bauelemente und Schaltungen, Integrierte Systeme, Sensorik, Theoretische Elektrotechnik
Förderung Förderung von 2010 bis 2017
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 175696353
 
Erstellungsjahr 2016

Zusammenfassung der Projektergebnisse

We have investigated the deployment of phase-insensitive fiber-based optical parametric amplifiers (FOPAs) in conventional long-haul wavelength-division multiplexing (WDM) transmission systems. Using both numerical methods and experiments, it has been shown that the performance of phase-insensitive FOPAs in long-haul transmission links can be comparable to that of erbium-doped fiber amplifiers (EDFAs) provided that lower power efficiency is accepted. In order to realize a practical FOPA in an optical transmission system, polarization-independent operation of the FOPA is necessary. Based on our investigations, it is essential to implement highly nonlinear fiber (HNLF) with well suppressed stimulated Brillouin scattering (SBS) (e.g. strained fiber) in a FOPA which employs the polarization-diversity scheme. In case pump phase-dithering is used for SBS enhancement of the HNLF, the number of RF dithering tones must be limited to three with a reduced maximum frequency level (e.g. about 800 MHz). As shown in our work, the choice of the maximum frequency of the pump phase-dithering tone has a direct impact on the SBS-induced signal degradation which can lead to an increased bit-error ratio. With this approach the FOPA can be used as an amplifier in the transmission network. Furthermore, the regenerative capabilities of a polarization-independent FOPA based on mid-link optical phase conjugation (OPC) has been demonstrated for the Kerr nonlinearity compensation of a 28-GBd polarization-division multiplexed 16-QAM signal in a 50-GHz spaced 5-channel WDM transmission over both dispersion-compensated and dispersion-uncompensated links. The nonlinearity compensation performances of both the FOPA-based OPC device and digital backpropagation were compared for up to 800-km transmission over dispersion-compensated transmission links. In the WDM scenario, the obtained Q2-factor improvement by the OPC when compared to the digital backpropagation and the transmission without any nonlinearity compensation were 0.4 dB and 0.9 dB, respectively. Therefore, in our experiments, the optical domain nonlinearity compensation proves to be a better approach than its digital domain counterpart for nonlinearity compensation of WDM signals. In general, for practical systems, it can be concluded that in transmission systems consisting of shorter spans of dispersion-uncompensated fibers utilizing distributed Raman amplification, the presence of a well-optimized mid-link polarization-independent OPC (based on the polarization-diversity loop scheme) can lead to a high Kerr nonlinearity compensation. The FOPA-based OPC device will require SBS-suppressed polarization-maintaining highly nonlinear fiber with a high nonlinear coefficient. In place of the PM-HNLF, a conventional HNLF can be used in the diversity loop. However, there should be a feedback from the diversity loop (e.g. using a coupler) in order to stabilize the input polarization of the pump.

Projektbezogene Publikationen (Auswahl)

 
 

Zusatzinformationen

Textvergrößerung und Kontrastanpassung