Burst-mode FEC performance for PON upstream channels with EDFA optical transients

The performance of forward error correction (FEC) based on Reed-Solomon coding is analyzed experimentally for a burst-mode upstream channel within a passive optical network (PON) testbed. During this analysis, the upstream FEC performance is impaired by inducing correlated and localized errors within the burst through the injection of optical transients. These transients emulate the optical signal variation associated with the add-and-drop events of wavelength channels within a long-reach optical link based on a chain of erbium doped fiber amplifiers (EDFAs). The robustness of the FEC has been analyzed by measuring the post-FEC bit error rate (BER) as a function of the amplitude of the emulated transients and their delay with respect to the transmitted bursts. A margin of approximately 4dB is demonstrated for the transient amplitude before the FEC degradation. Furthermore, while the post-FEC BER is strongly degraded by the emulated transients, the preFEC BER stays below the FEC threshold, demonstrating the importance of measuring the post-FEC BER in order to correctly characterize the FEC performance in PON upstream channels affected by optical transients

Fibre Optic Parametric Amplifiers For Transient Limited Optical Fibre Systems

The thesis explores fibre optical parametric amplifiers (FOPAs) to implement and develop the FOPA ability to provide transient free burst mode signal amplification, presenting potential applications in reach extended access networks and time-varying optical transmission systems. This document experimentally demonstrates FOPA as a potential drop-in amplifier candidate for transient limited optical systems by experimentally investigating and comparing transient effects in conventional fibre amplifiers. For example, future reach extended optical access networks. Additionally, this work provides evidence for transient free burst traffic amplification enabled by FOPA. A number of experimental techniques were implemented to demonstrate an ultra- fast response, high burst signal gain, and the ability to simultaneously amplify bi- directionally transmitted signals in a dual telecom band. Novel polarisation-insensitive FOPA employed in a 50 km reach extended access network link to achieve clean burst mode signal amplification. PI-FOPA targeted varied burst durations and burst traffic density amplification to evaluate performance compared to a commercial erbium-doped fibre amplifier (EDFA) and a discrete Raman amplifier. FOPA enhances link receiver sensitivity by >3 dB compared to EDFA and Raman amplifier for a varied burst duration amplification from 70 µs to 5 µs. For high burst traffic density amplification from 5% to 97%, FOPA allows burst traffic amplification up to 97% traffic, while EDFA and discrete Raman amplifier traffic density amplification was limited to 15% and 30%. We first presented a bi-directional non- burst and burst signal amplification by implementing a novel dual-band FOPA setup. FOPA achieved polarisation insensitive net gain of >16 dB for >50 nm apart signals in C and L bands. FOPA's ability to provide a wide broadband gain of ~10THz is utilized to amplify a non-burst and bursty signal in a dual-band transmission with a single in-line PI-FOPA amplifier simultaneously