Two photon absorption in Mn-doped ZnSe quantum dots

0030-4018/$ see front matter 2010 Elsevier B.V. A doi:10.1016/j.optcom.2010.01.053 * Corresponding author. E-mail addresses: [email protected] (G.R. Kumar), sh (S. Mahamuni). 1 Present address: K.J. Somaiya College of Sc. & Comm 077, India. The nonresonant third order nonlinear optical properties of three different sized Mn-doped ZnSe quantum dots (QDs) are investigated. The nonlinear absorption is measured at 532 nm using 35 picosecond laser pulses in an open-aperture Z-scan setup. Two photon absorption (2PA) cross-section in ZnSe QDs is found to be three orders of magnitude higher than its bulk value. These nanostructures show size dependent nonlinear absorption coefficients. It is found that the 2PA further enhances with decrease in size of the QD and is twice that of its undoped counterpart due to change in the local electric field. 2010 Elsevier B.V. All rights reserved.