Synthesis And Third-order Optical Nonlinearities Of Hyperbranched Metal Phthalocyanines

A series of novel organic hyperbranched metal phthalocyanines （HMePcs） weresynthesized for investigating their third-order nonlinear optical （NLO） properties. Thethird-order NLO coefficient was measured by Z-scan technique with a pulsedQ-switched Nd:YAG nanosecond laser at532nm. The hyperbranched phthalocaninesoligomers showed large molecular cubic hyperpolarizabilities （γ） whose values wereof the order of10^-29esu. The variation of substituent groups of and center metal ofHMePc influenced the third-order optical nonlinearity. The presence ofelectron-withdrawing substituents-fuoro in the phthalocyanine brings about anoticeable improvement of the third-order nonlinear susceptibility x³in these systemsand the third-order nonlinear susceptibility x³values of different metalhyperbranched metal （Cu, Ni, Co） phthalocanines oligomers were found to decreasein the order CuPc>NiPc>CoPc.