The Reduction of Harmonic and Intermodulation Distortions with a Cascaded Mach-Zehnder Molulator

Abstract

A cascaded two-stage Mach-Zehnder modulator is used to suppress the harmonic and intermodulation distortions simultaneously. The modulation electric fields are applied on the first and second stages in the y and z directions of z-cut lithium niobate crystal, respectively. Because of the inherent versatility of the adjustable modulation parameters, superior linear modulation response can be achieved. When -50 dB nonlinear suppression is required, the modulation depth of 7.5% can be obtained.