Reduction in DC-Drift in LiNbO3-Based Electro-Optical Modulator

Abstract

This study involves the results of research on short-term and long-term DC-drifts in electro-optical modulators based on annealed proton exchange waveguides in LiNbO3 crystals after wafer pre-annealing. The relaxation time of the DC-drift of the operating point for a short-term drift is measured in minutes, and for a long-term drift it is measured in hours and days. DC-drift was measured by applying bias voltage and changing crystal temperature. The obtained results show significant impact on the stability of operating point in EO-modulators after treatment of defective structure of the near-surface layer of a LiNbO3 crystal. Treatment of the disturbed near-surface layer of a LiNbO3 crystal results in the simultaneous reduction in short-term DC-drift and increase in operation stability of electro-optical modulators during long-term measurement of temperature by activation energy calculation.

The Optimal Operating Point for Linearizing an Integrated Optical Lithium Niobate Directional Coupler Modulator

“…The goal of this extended work was to conduct a more detailed investigation of the factors influencing the suppression of third-order intermodulation distortion. Particular attention will be paid to practical aspects related to setting and stabilizing the DCM at the optimal operating point, such as producing a directional coupler with a splitting ratio close to 100% and reducing DC drift of the operating point [33][34][35].…”