|Thesis abstract: |
Next generation passive optical networks will prove fundamental for the access and aggregation segment for broadband residential services and for mobile networks. Wavelength division multiplexed passive optical networks (WDM PON) appear a promising and suitable solution for the capacity requirements of next generation access networks as they allow the exploitation of the whole bandwidth of the optical fiber. WDM PON topologies based on color agnostic e.g. colorless solutions are favored as they allow for scale economies for the optical network units (ONUs) and for inventory cost savings. Among WDM technologies the self-seeding in reflective semiconductor optical amplifiers (RSOA) represents a smart solution, which avoids the need of external seeding sources and consequently also Rayleigh Back Scattering impairments, realizing not only a colorless source but also a self-tuning transmitter for ONUs.
This thesis wants to contribute to the study and development of a colorless self-tuning network embedded transmitter supporting up to 10-Gb/s data rates, within the European project ERMES (http://ermes-project.eu/).The proposed transmitter is based on a deeply-saturated and directly modulated RSOA, which act as multifunction active chip in a self seeding modulable laser cavity, whose passive part is constituted by the PON elements themselves. The work will rely both on experimental and theoretical activities aiming to analyze the peculiar characteristics of the transmitter source. In particular the work will focus on the evaluation and understanding of the influence of the main cavity parameters (cavity losses, cavity length, AWG optical bandwidth, connecting fiber characteristics, RSOA gain properties and chromatic dispersion) on the transmitter modulation quality. The analysis should provide solutions to cope with possible impairments and to fulfill the requirements of the access network, providing data rates as high as 10 Gb/s over propagation distances of tens of kilometers.