Linear and nonlinear electro-optic modulations of BaTiO3-crystal thin-film waveguides for 100GHz modulators

In this work, two electro-optic (EO) modulation schemes based on the Pockels effect - the quasi-linear and nonlinear EO modulation are compared and analyzed. Then, we find that the modulation efficiencies with these two schemes are at the same level relation of V
_π
and L, but the quasi-linear scheme has to face the critic limitation in the realistic EO modulation implementation process. Thereby, with nonlinear EO modulation the feasible potential of single bandwidths higher than 100 GHz are theoretically demonstrated for waveguide EO modulators with c-axis oriented BaTiO
₃
crystal thin-films having an effective r
₅₁
value of 550 pm/V and an absolute birefringence value of lower than 0.005.