Phase-polarization ensemble modulation effect of a BaTiO₃ crystal film waveguide on Mach-Zehnder interferometer...

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.