Measurement of Nonlinear Properties for PEI Tetra Sulfonated Indium Phthalocyanine Compounds Self-Assembly Film Using Improved Tophat Z-Scan Technique

Abstract

The nonlinear refraction and absorption properties of a PEI (phthalocyanine indium) tetrasulphonated chlorinated phthalocyanine electrostatic self-assembled film were studied using a simple and high sensitivity technique. We adopted picosecond laser pulses as source light and modified top-hat Zscan technique with a disk and a small aperture to explore the nonlinear refraction of the film. Experimental results show that the measuring sensitivity is increased by two orders of magnitude. Through theoretical fitting, we obtain the nonlinear refraction index and nonlinear absorption coefficients of the film are 2.1×10-14 m2/W and 2.4×10-7 m/W, respectively.