Temporal response of the second-order nonlinearity in poled bulk-fused silica under field reversal

When an electric field is applied to a heated piece of bulk silica glass, which is subsequently cooled with the field applied, a permanent second order nonlinearity is formed. Here we examine the formation of the nonlinearity in situ via real-time observation of the second harmonic signal. The dynamics of the growth and decay of the signal are dependent on field polarity, sample history and ambient environment during heating. The in situ dynamics indicate that under field reversal, there can be a long delay ins creating or destroying the nonlinearity.