COMPARISON OF THE PROPAGATION PERFORMANCE OVER STANDARD DISPERSIVE FIBER BETWEEN INP-BASED PI-PHASE-SHIFTED AND SYMMETRICAL MACH-ZEHNDER MODULATORS

We estimated and experimentally verified the output phase and intensit y characteristics versus the applied voltage of an InP-based Mach-Zehn der modulator from the measured data of refractive index and loss vari ations specific to the phase section material (Fabry-Perot method). We have then simulated the propagation performance of a Mach-Zehnder mod ulator taking into account the possible phase-shift between both arm o f the interferometer, In total agreement with experimental results, we show that the simple single-arm modulation scheme does not require hi gh voltages and that the pi-phase-shifted Mach-Zehnder modulator is fa r more convenient for a 10-Gb/s propagation over standard dispersive f iber than a symmetrical modulator.