DC drift of Z-cut LiNbO3 modulators

DC drift characteristics of z-cut LiNbO₃ modulators with oxide buffer layers were studied with respect to their acceleration factors and long-term reliability. Analysis of more than 120 data points of measured drift tests indicate a slight nonlinear contribution by the starting bias voltage Vs to drift acceleration, with a factor equal to Vs^1.27. However, the observed nonlinearity is shown to have little affect on reliability estimations due to a dominant contribution from temperature activation energy; Ea=1.1 eV. The dc drift failure rates are estimated to be on the order of tens of failures in time for 20 years at 55°C.