Theoretical analysis of thermal/electric-field poling fused silica with multiple-carrier model

Using the multiple-carrier model under the step-profile approximation of the charge density distribution, expressions for the width and electric field distribution in the depletion region of fused silica samples after formed by thermal/electric-field poling are derived. Theoretical results show that the peak electric field is located in the inner of the depletion region, and that the chemical formation of H+/H3O+ may take place in the negatively depleted region. The depletion region width and the second-order susceptibility, which are approximately 10 μm and approximately 0.35 pm/V for the normal thermal/electric-field poling in air, respectively, are proportional to the square root of the applied dc voltage, and agree well with previous experimental results.