The third-order nonlinear optical susceptibilities, χ<sup>(3)</sup> , of composite films consisting of nanocrystalline Au and ZnO particles were investigated by use of a degenerate four-wave mixing scheme. The maximum value of χ<sup>(3)</sup> , measured at a laser wavelength of 532 nm and a pulse duration of 70 ps, was ~2×10<sup>-6</sup>esu . Also, this χ<sup>(3)</sup> value was achieved with small absorption (the surface-plasmon peak was at the 615-nm wavelength). Our composite materials showed no discernible degradation after they were subjected to irradiation for a total of 3×10<sup>7</sup> high-intensity pulses (24 Mw/cm <sup>2</sup> , 70-ps pulse duration at 500 Hz) during 16 h of testing.
© 2003 Optical Society of America
Hongbo Liao, Weijia Wen, George K. L. Wong, and Guozhen Yang, "Optical nonlinearity of nanocrystalline Au/ZnO composite films," Opt. Lett. 28, 1790-1792 (2003)