Abstract

All optical wavelength converters will become key devices in photonic switch blocks and will also be important for implementation of flexible wavelength multiplexed networks.¹ The converters based on four wave mixing in semiconductor optical amplifiers (SOA's) are valid candidate because they can process high bit rate signals, present a large detuning bandwidth and the frequency translation is independent of signal modulation format. Moreover such converters operates spectral inversion on the converted signal, allowing the compensation of fibre dispersion and Kerr effect² if placed in the midway of an optical link. In this contribution we show the transmission performance of long distance optical links (Fig. 1) which contain a certain number of converters, optical filters and fibre amplifiers. This kind of links could be a simplified model of a transmission path along an optical network that comprises several node in which wavelength conversion occurs. The transmission performances are evaluated in terms of the eye penalty. The pulse train at the transmitter consists of a random sequence of bit in NRZ format, at a bit rate of 10 Gbit/s. The nonlinear Schroedinger equation describing the pulse propagation in the fibre is solved by using the split-step method.³

© 1995 IEEE