We report direct measurements of both magnitude and spectral dispersion of two-photon absorption in organic-capped CdSe quantum dots and three-photon absorption in organic-capped ZnO quantum dots by the use of open-aperture Z-scan technique with femtosecond laser pulses in the wavelength range of 720-950 nm. We find that these nonlinear coefficients are at least an order of magnitude greater than their bulk counterparts. Our experimental data are compared with theories and the rules for wavelength scaling are discussed.
© 2005 Chinese Optics Letters
(190.4180) Nonlinear optics : Multiphoton processes
(190.4400) Nonlinear optics : Nonlinear optics, materials
(190.4720) Nonlinear optics : Optical nonlinearities of condensed matter
(190.5970) Nonlinear optics : Semiconductor nonlinear optics including MQW
Wei Ji, Yingli Qu, Jun Mi, Yuangang Zheng, and Jackie Y. Ying, "Wavelength scaling for multiphoton absorption in semiconductor quantum dots," Chin. Opt. Lett. 3, S203-S204 (2005)