TDEC metric in 50G-PON: analytical and experimental investigation on several implementation aspects

We analyze the metrology of transmitter and dispersion eye closure (TDEC) as defined in a 50G passive optical network (50G-PON) for assessing transmitter quality. First, we present a theoretical evaluation for adapting TDEC to 50G-PON, where equalized bandwidth limited avalanche-photodiode-based receivers are expected. We optimize the parameters for a proper numerical evaluation and provide some guidelines for implementing the metric. We also show that TDEC can be measured with both sampling and real-time oscilloscopes provided that there are enough samples for the latter. A comparison of two techniques, one noiseless and one considering noise enhancement, for computing the coefficients of the equalizer is also provided. Finally, an experimental comparison between a Mach–Zehnder modulator and an electroabsorption-modulated-laser-based transmitter is carried out with different extinction ratios and fiber lengths, showing that TDEC can effectively predict the receiver sensitivity penalty.