Phase-polarization ensemble modulation effect of a BaTiO3 crystal film waveguide on Mach–Zehnder interferometer electrooptic intensity modulators

In this work, based on the nonlinear electrooptic (EO) modulation model, the relationship between the polarization states and the birefringence modulation caused optical phase of c-axis barium titanate (BaTiO3) crystal film is investigated first. Then, under an ensemble effect of phase-polarization modulation (PPM), the photon polarization behavior of a lightwave in a BaTiO3 film waveguide and its dynamic conversion process is clearly presented. Further, the optical output and optical phase changes of a Mach-Zehnder interferometric (MZI) type EO intensity modulator based on a dynamic nonlinear optical birefringence modulation are theoretically modeled. As a result, the systematic simulations show that, for one-wave (2π) optical phase modulation (OPM), the full width at half-maximum of the output signal is efficiently compressed 30% more than the current OPM. Finally, the improvements of the MZI output signal by the PPM scheme are in accord with the experimental results.