[6p-A414-1~21] 3.8 Optical measurement, instrumentation, and sensor

[6p-A414-13] Theory of closed-aperture Z-scan for nonlinear nanocomposite media possessing saturable absorption and high order nonlinear refraction

〇Shunsuke Matsushima¹, Yasuo Tomita¹ (1.Univ. of Elec.-Comm.)

Keywords:nanocomposite, nonlinear optics, semiconductor quantum dot

Z-scan method which was originally developed by Sheik-Bahae et al. as the high sensitive characterization method of the third-order nonlinear optical properties, has been extended to the theories about the nonlinear optical medium with multiphoton absorption and simultaneous third- and fifth-order nonlinear refraction. We observed high order nonlinearities with saturable absorption in our newly developed polymer nanocomposite materials highly dispersed with semiconductor CdSe quantum dots (QDPNC), and reported Z-scan theory for them. However, this theory based on the Gaussian decomposition method is limited to the case where the fifth-order nonlinear phase shift is much smaller than the third order one. In this report, we describe a generic closed-aperture Z-scan theory for nonlinear media possessing both SA and simultaneous third- and fifth order nonlinear refraction without such limits.