Second-harmonic generation, one of the second-order nonlinear optical properties of thermally and electrically poled WO><sub>3</sub>—TeO><sub>2</sub> glasses, has been examined. We poled glass samples with two thicknesses (0.60 and 0.86 mm) at various temperatures to explore the effects of external electric field strength and poling temperature on second-order nonlinearity. The dependence of second-harmonic intensity on the poling temperature is maximum at a specific poling temperature. A second-order nonlinear susceptibility of 2.1 pm/V was attained for the 0.60-mm-thick glass poled at 250°C. This value is fairly large compared with those for poled silica and tellurite glasses reported thus far. We speculate that the large third-order nonlinear susceptibility of WO><sub>3</sub>– TeO><sub>2</sub> glasses gives rise to the large second-order nonlinearity by means of a <i>X</i><sup>(2)</sup> = 3<i>X</i><sup>(3)</sup> <i>E</i><sub>dc</sub> process.
© 2000 Optical Society of America
(160.2750) Materials : Glass and other amorphous materials
(160.4330) Materials : Nonlinear optical materials
(190.2620) Nonlinear optics : Harmonic generation and mixing
(190.4400) Nonlinear optics : Nonlinear optics, materials
Katsuhisa Tanaka, Aiko Narazaki, and Kazuyuki Hirao, "Large optical second-order nonlinearity of poled WO3—TeO2 glass," Opt. Lett. 25, 251-253 (2000)