Comparison of the propagation performance over standard dispersive fiber between InP-based π-phase-shifted and symmetrical Mach-Zehnder modulators

Abstract

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