Near resonant and nonresonant third-order optical nonlinearities of colloidal InP/ZnS quantum dots
He, T. C.
Demir, Hilmi Volkan
Date of Issue2013
School of Electrical and Electronic Engineering
We have investigated the third-order optical nonlinearities of high-quality colloidal InP/ZnS core-shell quantum dots (QDs) using Z-scan technique with femtosecond pulses. The two-photon absorption cross-sections as high as 6.2 x10^3 GM are observed at 800 nm (non-resonant regime) in InP/ZnS QDs with diameter of 2.8 nm, which is even larger than those of CdSe, CdS, and CdTe QDs at similar sizes. Furthermore, both of the 2.2 nm and 2.8 nm-sized InP/ZnS QDs exhibit strong saturable absorption in near resonant regime, which is attributed to large exciton Bohr radius in this material. These results strongly suggest the promising potential of InP/ZnS QDs for widespread applications, especially in two-photon excited bio-imaging and saturable absorbing.
DRNTU::Engineering::Electrical and electronic engineering
Applied physics letters
© 2013 American Institute of Physics. This paper was published in Applied Physics Letters and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following official DOI: http://dx.doi.org/10.1063/1.4776702. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.