Harmonic and intermodulation performance of dual-electrode Mach-Zehnder electro-optic modulators with multicarrier RF input

Large signal analysis of the dual-electrode Mach-Zender modulator (DE-MZM) is presented and closed-form expressions are obtained for harmonics and intermodulation performance of the DE-MZM excited by a multi-carrier RF input signal. The special case of a DE-MZM excited by three equal-amplitude carriers is considered in detail. The results obtained show that the amplitude of the second-order components is highly sensitive to the phase bias. The results also show that for values of phase bias close to zero or 180 degrees the second-order components are dominant and for small range values around 90 degrees the odd-order components are dominant.