Forward error correction in WDM PON using spectrum slicing

This paper presents experimental results of the introduction of FEC (forward error correction) in optical access network architectures operating at 625 Mb/s. We have first tested a Reed Solomon code on a point to point architecture to confirm the theoretical 3 dB gain in link budget. The innovative architecture is a wavelength division multiplexed passive optical network (WDM PON) using spectrum slicing and a reflective semiconductor optical amplifier (RSOA) to generate upstream signals. Optical carrier supply by spectrum slicing and modulation and amplification by RSOA is a way of reducing costs in WDM PON but it gives a noisy transmission due to excess intensity noise of broadband sources, Amplified Spontaneous emission of the SOA and beat noise at detection. In this case, adding FEC has more effect and it results in an increased link budget of 5.5 dB. FEC are a simple and efficient solution to compensate for penalties introduced by low cost components in innovative architectures like WDM PON.