Optical second-order nonlinearity of poled borosilicate glass containing CuCl

The effect of surface etching on second-harmonic (SH) intensity and Maker f ringe pattern have been examined for poled borosilicate glasses containing CuCl. A drastic decrease in the SH intensity was observed with anode-side s urface etching, while such a decrease did not appear when the cathode-side surface etching was carried out. However, after 20 mu m etching of the anod e-side surface, a decrease in SH intensity with the cathode-side etching wa s observed. For some samples, the theoretical Maker fringe pattern derived on the assumption that the SH wave is generated from a thin layer near the anode-side surface is in good agreement with the experimental one. On the o ther hand, other samples show oscillation in the fringe, which originates f rom the interference of SH waves generated from both surfaces. These result s suggest that the nonlinear layer is present at both surfaces, although it is much weaker near the cathode. It is thought that the origin of the nonl inearity is attributable to migration of Cu+ and Cl-. (C) 2000 American Ins titute of Physics. [S0021-8979(00)01218-4].