The third-order nonlinear optical susceptibilities, χ(3) , 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(3) , measured at a laser wavelength of 532 nm and a pulse duration of 70 ps, was ~2×10-6esu . Also, this χ(3) 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 3×107 high-intensity pulses (24 Mw/cm 2 , 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)