Table of Contents
Physics Research International
Volume 2012, Article ID 161572, 9 pages
Research Article

Closed-Aperture Z-Scan Analysis for Nonlinear Media with Saturable Absorption and Simultaneous Third- and Fifth-Order Nonlinear Refraction

1Department of Engineering Science, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan
2Research Institute for Electronic Science, Hokkaido University, Souseitou, Kita 21, Nishi 10, Kita-ku, Sapporo 001-0021, Japan

Received 11 May 2012; Accepted 9 July 2012

Academic Editor: Michael R. Gleeson

Copyright © 2012 Xiangming Liu and Yasuo Tomita. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We present a theory of open- and closed-aperture Gaussian beam Z-scan for nonlinear optical materials with saturable absorption and high-order nonlinear refraction. We show that an approximate expression for a transmitted intensity through the nonlinear optical material is possible by means of the Adomian’s decomposition method and the thin film approximation. The theory is applied to semiconductor CdSe quantum dot-polymer nanocomposite films. It is shown that the theory well explains measured results of open- and closed-aperture transmittances in the Z-scan setup. It is also shown that the nanocomposite film possesses simultaneous third- and fifth-order nonlinear refraction as well as saturable absorption of a homogeneously broadened type.