40-Gb/s TDM-PON downstream with low-cost EML transmitter and 3-level detection APD receiver

We report a cost-effective 40-Gb/s TDM-PON downstream utilizing an integrated DFB-EAM in OLT and an APD-based 3-level detection receiver in ONU, achieving a high power budget of 23.4 dB in real time operation

Access and metro network convergence for flexible end-to-end network design

This paper reports on the architectural, protocol, physical layer, and integrated testbed demonstrations carried out by the DISCUS FP7 consortium in the area of access - metro network convergence. Our architecture modeling results show the vast potential for cost and power savings that node consolidation can bring. The architecture, however, also recognizes the limits of long-reach transmission for low-latency 5G services and proposes ways to address such shortcomings in future projects. The testbed results, which have been conducted end-to-end, across access - metro and core, and have targeted all the layers of the network from the application down to the physical layer, show the practical feasibility of the concepts proposed in the project

Development of high capacity transmission systems for future optical access networks

The cost-sensitivity of NG-PON2 and future optical access networks, employing wavelength division multiplexing (WDM) technology, may preclude the use of conventional LiNbO3-based intensity and I/Q modulators, as they are currently too expensive for use in the access domain. Cost-effective directly modulated lasers (DMLs) and electro-absorption modulated lasers (EMLs) will need to be employed and, thus, are expected to be integral components in the realisation of tunable laser sources for future optical access networks. The limitations of DMLs and EMLs as transmitters merit thorough investigation to further understand how these devices can be adapted or optimised for use as tunable laser sources in future optical access networks. In this thesis, the transmission performance of a directly modulated DFB laser (DML) and an externally modulated DFB laser monolithically integrated with an EAM (EML), are investigated. The performance of both devices under 12.5 Gbit/s NRZ-OOK modulation are evaluated for transmission over standard single-mode fibre (SSMF) in an IM/DD test-bed, with a view to further understanding the limitations of DMLs and EMLs in 10 Gbit/s IM/DD systems. Particular attention is given to the frequency chirp of the devices and how the chirp affects the performances of the devices for transmission over SSMF up to 50 km in length. Numerical models, which were developed in MATLAB, are utilised to simulate the characteristics and transmission performances of both the DML and EML. The latter half of this thesis is focused on the development of a self-seeded Fabry-Pérot (SS-FP) laser. The SS-FP laser is optimised and characterised, and the transmission performance of the directly modulated SS-FP laser over SSMF is evaluated in an IM/DD test-bed. Two intensity modulation (IM) formats are assessed, 12.5 Gbit/s NRZ-OOK and 12.5 Gbaud/s (25 Gbit/s) multilevel PAM-4, both IM formats are compatible with 10G class optical components and legacy PON deployments. The SS-FP laser holds potential for photonic integration, justifying its consideration as a candidate tunable laser source for next generation PONs and future optical access networks