Electrooptic characteristics of thin-film PLZT waveguide using ridge-type Mach-Zehnder modulator

The design, characterization, and drift due to electrical bias (DC drift) of thin-film lanthanum-doped lead zirconate titanate (PLZT) waveguide is reported using a Mach-Zehnder modulator. The mechanism of the electrooptic responses based on hysteresis of the applied field is proposed to understand the behavior of the device. It is shown that the thin film exhibits a Kerr effect having a coefficient value of 5×10/sup -18/ (m/V)
²
. It is reported that by utilizing hydrogen-deficient dry etching, the DC drift is improved by a factor of 3.5. In addition, the verification of the operation of a PLZT-based device for more than 1400 h at 70°C is reported, for the first time.