Femtosecond Z-scan investigation of third-order optical nonlinearity in PbS-polymer nanocomposite

Summary form only given. There is much current interest in the nonlinear optical properties of quantum confined semiconductor nanocrystals, particularly for their potential use in nonlinear photonic devices. Recently we have successfully synthesized an optically homogenous PbS-polymer nanocomposite by in-situ polymerization of bicontinuous microemulsions. The PbS nanocrystals with an average size of 5 nm were formed in aqueous domains randomly embedded in the methyl methacrylate (MMA)/acronitrile (AN)//spl omega/-methoxy poly(ethylene oxide)/sub 40/ undecyl-/spl alpha/-methacrylate (C/sub 1/-PEO-R-MA-40) copolymer network. We present an experimental study of third-order optical nonlinearity in the PbS-polymer nanocomposite, using the Z-scan technique with linear polarized 120-fs laser pulses at 780-nm wavelength. The mechanisms responsible for the observed optical nonlinearity are also discussed.