Nonlinear Properties and S-matrix Description of a Mach-Zehnder Modulator

Mach-Zender Modulators (MZMs) are widely used electro-photonic devices for external modulation of lightwave signals. The transmission characteristics of MZM are nonlinear, therefore the device can be used not only for applications that require its linear behavior but also for those which involve non-linear behavior like mixing and frequency multiplication.

One important issue in use of MZM in microwave photonic devices is the way MZMs are described in terms of their microwave parameters. In this paper we present description of MZM with scattering matrix formalism and limitations of such approach. Moreover, we present the possible non-linear behavior of MZMs for electrical and opto-electrical mixing over different biasing voltages - as an extension of linear approach.