Nonresonant-type homogeneous Bi<sub>2</sub>O<sub>3</sub>–B<sub>2</sub>O<sub>3</sub>–SiO<sub>2</sub> glasses were prepared by melting. The third-order optical nonlinear susceptibility χ<sup>(3)</sup>, which was determined by measurement of third-harmonic generation, increased with increasing concentrations of Bi<sub>2</sub>O<sub>3</sub> in the glass. The maximum χ<sup>(3)</sup> estimated was 9.3×10<sup>−12</sup> esu in glass that contained 92 wt. % of Bi<sub>2</sub>O<sub>3</sub>. χ<sup>(3)</sup> values of these glasses were enhanced by the small optical bandgap. These glasses also exhibited an ultrafast response time, less than 200 fs, when a degenerate four-wave mixing method with a femtosecond laser was used, indicating that the nonlinearity of these glasses originated mainly from pure electronic polarization.
© 1999 Optical Society of America
(190.4380) Nonlinear optics : Nonlinear optics, four-wave mixing
(190.4400) Nonlinear optics : Nonlinear optics, materials
(190.7110) Nonlinear optics : Ultrafast nonlinear optics
(320.7130) Ultrafast optics : Ultrafast processes in condensed matter, including semiconductors
Naoki Sugimoto, Hirohisa Kanbara, Seiji Fujiwara, Koichiro Tanaka, Yutaka Shimizugawa, and Kazuyuki Hirao, "Third-order optical nonlinearities and their ultrafast response in Bi2O3–B2O3–SiO2 glasses," J. Opt. Soc. Am. B 16, 1904-1908 (1999)