Second-harmonic generation was observed in Ge<sub>20</sub>As<sub>25</sub>S<sub>55</sub> chalcogenide glass irradiated by an electron beam. The second-harmonic intensity increased with increasing electron-beam current and accelerating voltage. The second-harmonic generation in Ge<sub>20</sub>As<sub>25</sub>S<sub>55</sub> glass was caused by the space-charge electrostatic field that was generated by irradiation of an electron beam. Second-order nonlinearity <i>X</i><sup>(2)</sup> as great as 0.8 pm/V was obtained. The results of measurements of thermally stimulated depolarization current indicated that the glass was poled in the thin layers of its surface (several micrometers) and that the nonlinearity was stable.
© 2001 Optical Society of America
Qiming Liu, Fuxi Gan, Xiujian Zhao, Katsuhisa Tanaka, Aiko Narazaki, and Kazuyuki Hirao, "Second-harmonic generation in Ge20As25S55 glass irradiated by an electron beam," Opt. Lett. 26, 1347-1349 (2001)