This paper describes a new model for the breakdown voltage of SiO2 fiber coupler using the Pockel effect and empirical
equation. The model is evaluated by using the coupling coefficient and the changes in the refractive index. We found that
the breakdown voltage is in the order of 102 volt correspond to coupling coefficient by the order of mm-1. Increasing the
value of coupling coefficient between the electrodes leads to a reduction in the breakdown voltage.