Polarization-Resolved Degenerate Four-Wave Mixing Of Cds Nanocrystals In A Nonresonant Region

The third-order susceptibilities of various concentrations of TOPO-passivated CdS nanocrystals (NCs) with the size near the Bohr radius were investigated using polarization-resolved degenerate four-wave mixing (DFWM) in a nonresonant excitation region with 532 rim wavelength and 8 ns pulse width. The second hyperpolarizabilities and of the CdS NCs were similar to 1.25x 10(-42) m(5)/V-2 and similar to 3.66x 10(-43) m(5)/V-2, respectively. The ratio (/) of the hyperpolarizabilities was similar to 0.29 that indicated a large contribution of electronic polarization process to the third-order nonlinearity of CdS NCs. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Wembeim