title: Tunable time response of the nonlinearity of nanocomposites by doping semiconductor quantum dots.
abstract: We report an approach to achieving a tunable time response of the nonlinearity of nano-Ag:polymer nanocomposites. The response time of the nonlinearity of the nanocomposite made of Ag nanoparticles dispersed in poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] matrix can be tuned by adjusting the doping concentration of CdTe(0.13)S(0.87) quantum dots. An ultrafast response time of 14.5 ps is achieved for a doping concentration of 27%. Moreover, the third-order nonlinear susceptibility, achieving the order of 10(-5) esu, is one order of magnitude larger than that of the undoped nanocomposite. An ultrafast and low-power photonic crystal all-optical switching is also realized based on the photonic bandgap shift.
authors.affiliation: State Key Laboratory for Mesoscopic Physics & Department of Physics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Hu
authors.forename: Jiaxiang
authors.initials: J
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.forename: Qihuang
authors.initials: Q
authors.lastname: Gong