Abstract
To clarify the eventual role of confinement in the below-band-gap nonlinear response of semiconductor nanocrystals, we performed two-photon absorption (TPA) measurements in semiconductor doped glasses (SDG). In previous experiments employing 30 ps pulses it was not possible to obtain accurate values of 1mχ(3) since the nonlinear transmission was affected by the absorption of free carriers generated by TPA1. This is a common problem in TPA measurements, and becomes more severe whenever a short thickness of material, or a small semiconductor volume fraction as in our case, forces to use high intensities to have a detectable absorption. A straight way out is to reduce the number of generated free carriers by using shorter pulses1, and to this end a femtosecond travelling wave parametric generator (TOPG)2 appeared the best solution to provide also the desired tunability.
© 1996 IEEE
PDF ArticleMore Like This
G. P. Banfi, V. Degiorgio, M. Ghigliazza, H. M. Tan, and A. Tomaselli
QThF3 European Quantum Electronics Conference (EQEC) 1994
A.A. Lipovskh, E.V. Kolobkova, and V.D. Petrikov
QThB7 European Quantum Electronics Conference (EQEC) 1996
Mark D. Dvorak, W. Andreas Schroeder, David R. Andersen, Arthur L. Smirl, and Brian S. Wherrett
CThP3 Conference on Lasers and Electro-Optics (CLEO:S&I) 1993