Erasing process of thermally poled optical nonlinearities in silica glasses with KrF excimer laser pulses

We observed a second-order optical nonlinearity of chi(33)((2))=0.30 pm/V in a fused silica glass poled under the condition of static electric field of 4 kV/mm at 260 degrees C. The nonlinearity layer localized in die surface region contacted on the positive electrode during poling in a thickness comparable with or thinner than the interaction length of 22 mu m. Even though a nonlinearity phase formation was not observed hi synthetic silica glass under the same condition, the poling induced a nonlinearity of 0.24 pm/V by exposing the sample to X-ray radiation before poling. We also observed that 248-nm pulses as low as 10 mJ/cm(2) from a KrF excimer laser erased die nonlinearity.