Growth and decay of the electrooptic effect in thermally poled B/Ge codoped fiber

Using an in situ technique for measuring the induced electrooptic effect during poling, we have studied the growth and decay characteristics of thermally poled twin hole B/Ge codoped fiber devices. The decay characteristic measured at elevated temperatures were best fitted with a stretched exponential function, indicating a distribution of relaxation times is present in this material. Using the Arrhenius relation, we calculate an activation energy for the stability of the electrooptic effect with this material and poling geometry in the range from 25 to 28 kJ/mol (0.28-0.31 eV), corresponding to a lifetime at 298 K of approximately 45 days.