Plasmonic electro-optic modulators on lead zirconate titanate platform.

The advancement in material platforms exhibiting strong and robust electro-optic effects is crucial for further progress in developing highly efficient and miniaturized optoelectronic components with low power consumption for modern optical communication systems. In this work, we investigate thin-film lead zirconate titanate (PZT) substrates grown by a chemical solution deposition technique as a potential platform for on-chip plasmonic electro-optic modulators. A high modulation depth (>40 %) is achieved with 15 μm-long electro-optic directional coupler modulators. An unusual cutoff in the modulation frequency response at ∼200 kHz is observed and further studied with respect to possible reorientation effects. Second-harmonic generation signals are found influenced by the externally applied electric field, indicating that the domain reorientation effect can be responsible for the unusual frequency response observed.