Rapidly tunable all-optical wavelength converter based on single semiconductor optical amplifier delay interferometer

We demonstrate a rapidly tunable 10 Gb/s all-optical wavelength converter based on a semiconductor optical amplifier delay interferometer and a tunable laser. It uses a 16-channel 100 GHz-spacing digitally tunable multifrequency laser based on a novel external-cavity laser design. The bit sequence on the incoming wavelength is converted alternatively to different wavelengths. Power penalties are 1.1 dB for 30 ns guard-time spacing between wavelength packets.     

SOA nonlinearities in 4 × 25 Gb/s WDM pre-amplified system for 100-Gb/s Ethernet

A simulation analysis of the impact that the nonlinear response of a semiconductor optical amplifier (SOA) has in a four-channel WDM pre-amplified transmission system is presented in the framework of the recently proposed extended-reach (40-km, 4 × 25 Gb/s) 100 Gb Ethernet link. Channel spacing values ranging from 200 to 800 GHz, and fiber losses between 0 and −20 dB are considered. A maximum power penalty of 4.5 dB is predicted for short fiber lengths and for the tightest channel plan. For short fiber lengths, the penalty drops by about 0.8 dB when moving from 400 to 800 GHz; whereas for long fiber lengths, the penalty increases by 0.2 dB, provided that an average dispersive fiber is utilized. The widely spaced channel plan then represents the best choice in terms of the analyzed physical effects to implement the next-generation 100 GbE link. Further, our numerical investigation includes a discrimination analysis that confirms cross-gain modulation as the main overall SOA nonlinear impairment in the analyzed architecture, and establishes ultra-fast carrier heating-induced FWM as responsible for the system performance difference observed as a function of channel spacing. The difference practically vanishes for fiber lengths above 30 km. Finally, the proposal of an equation that fits the simulated power spectrum density of the first-order four-wave mixing-generated product as a function of channel spacing is presented as an aid to validate our numerical results.     

A versatile modular computational tool for complex optoelectronic integrated circuits simulation

A novel graphical computational tool to simulate a wide variety of complex optoelectronic integrated circuits is presented. Based upon a modular approach, this tool reduces the optical circuit into a sequence of interconnected building blocks, each one performing a specific data-flow oriented function onto an input optical stream. The modularity and the flow-based interconnectivity makes this simulator flexible and powerful, yet intuitive. Its execution speed is evaluated using a sophisticated amplifier simulation module that is compared against its replica written in a text-based programming language. More than four times outperformance is reported. The simulator capabilities are further demonstrated through an application example in the field of optical data processing: the analysis of a semiconductor optical amplifier-based Mach–Zehnder interferometer operated as wavelength converter for signals modulated at 40 Gb/s. This simulator represents an attractive alternative to more traditional approaches.