Nonlinear optical behavior of metal octaphenoxy phthalocyanines: effect of distortion caused by the central metal

作者：Sanusi Sikiru O; Antunes Edith; Nyokong Tebello^*

来源：Journal of Porphyrins and Phthalocyanines, 2013, 17(10): 920-927.

DOI：10.1142/S1088424613500715

• phthalocyanine
• nonlinear optics
• hyperpolarizability
• third order susceptibility
• Z-scan
• reverse saturable absorption

In this work, we investigated the nonlinear optical absorption properties of chloroaluminum, chlorogallium, chloroindium, zinc and lead octaphenoxy phthalocyanines in a dimethyl sulphoxide solution using 5 ns pulses at 532 nm. Using the Z-scan technique, the nonlinear optical properties and the excited state absorption cross-sections were determined by fitting the Z-scan data. The k value was the highest for Pb derivative at 211, making it the best nonlinear optical material. In terms of hyperpolarizability, Pb derivative (containing a larger central metal) also gave the largest value followed by aluminum derivative (containing a small central metal). The distortion of the ring caused by the central metal is used to explain the hyperpolarizability values. Large nonlinear absorption coefficient values, beta(eff), in the range of 3.558-4.763 x 10(-9) cm. W-1 and low saturation fluence values, F-sat between 21.5-38.5 mJ. cm(-2), were obtained for these samples.

• 出版日期2013-10