Itsuro Morita

A novel transmitter for 320-Gb/s PDM-RZ-16QAM generation using electrical binary drive signals

We propose a new transmitter for 16QAM generation based on a combination of a dual-drive Mach-Zehnder modulator (DD-MZM) and a dual-parallel Mach-Zehnder modulator (DP-MZM) with electrical binary drive signals. By using the proposed transmitter, we successfully evaluated the performances of 224-Gb/s and 320-Gb/s PDM-RZ-16QAM signals.

Pattern-dependent bit error characteristics induced by asymmetrically filtering of CS-RZ signal

We have experimentally and numerically studied the pattern dependency in bit error characteristics of asymmetrically filtered CS-RZ signals. We have found that the bit error intensively occurs just after the end of a long sequence of 1s or 0s for strong asymmetrical filtering.

Optimum signal format for long-haul 40-Gbit/s-based WDM systems

The optimum signal format and the optimum FEC code rate for 40 Gbit/s-based WDM systems have been studied experimentally and numerically. We found that the bandlimited CS-RZ with highly efficient FEC of between 80 % and 90 % code rates is expected to be a suitable solution for ultralarge-capacity long-haul 40 Gbit/s WDM systems.