DC-Voltage-induced thermal shift of bias point in LiNbO/sub 3/ optical Modulators

Increasing thermal shift of a bias point is observed when dc voltage is applied to z-cut LiNbO/sub 3/ (LN) modulators having asymmetric design; whereas, stable thermal shift is observed in symmetric x-cut LN modulators. A growth of the thermal shift depends upon the amplitude, polarity, and duration of the applied voltage and constitutes a new criterion to reliability modeling of LN modulators.