The OptCom group has just successfully handled the local coordination of FOTONICA 2015, the Italian National Conference on Photonic Technologies, that took place in Turin from May 6th to 8th.

Optical coherent systems have an optimum transmission rate, at which some mitigation of non-linear effects spontaneously takes place.

The phenomenon occurs at a Baud rate which is neither the one of serial systems (28-32 GBaud) nor that of OFDM systems (in the hundreds of MBaud per subcarrier). It actually occurs between 2 and 8 GBaud, depending on system parameters. The higher the dispersion, the lower the optimum rate and, typically, the greater the potential mitigation.

In our OFC 2015 paper:

The EGN model (download EGN model paper) provides excellent accuracy in predicting the amount of non-linearity (or non-linear interference noise, NLI) affecting each channel in a WDM system.

See below the June 2014 news for more details. However, the EGN model is substantially more complex than the GN model.