Polarisation-independent InP push-pull Mach-Zehnder modulator for 20 Gbit/s soliton regeneration

Abstract
A new polarisation-independent InP Mach-Zehnder interferometer provides adjustable phase/intensity optical modulation under independent 20 GHz electrical control of the electrodes. Validation of the component as a regenerator for soliton systems is made through recirculating loop experiments. Error free transmission at 20 Gbit/s over more than 40000 km is obtained in push-pull mode for comparison with 8000 km under single-electrode control.