INVESTIGATION ON THE EXCITED STATE PROCESSES IN COVALENT-LINKED TETRATOLYLPORPHYRIN-PHTHALOCYANINE Ⅱ .NONLINEAR OPTICAL EFFECTS IN BINARY MOLECULES
Dou Kai Jin Chunming Zhao Jialong Zhou Fangce Luo Baozhu Qin Weiping Huang Shihua Yu Jiaqi Zhang Xinyi Xu Xurong(Changchun Institute of Physics, Academia Sinica, Changchun 130021)
A technique of the degenerate four-wave mixing (DFWM) has been employed to study the nonlinear optical effects in binary molecules of TTP-O-Pc and TTP-O-(CH2)5-O-Pc. The third-order nonlinear susceptibility of x(3)in TTP-O-PC is increased by over two orders of magnitude compared with TTP and PC. With the increase of covalence length between TTP and PC from -O- to -O-(CH2)5-O-, x(3) of the latter is 3×10-9 esu that is 5 times of that of the former. The enhancement of the optical nonlinearity for binary molecules is attributed to the charge transfer. The inverse saturation absorption which is found in TTP and PC disappears in TTP-O-Pc and TTP-O(CH2)5-O-Pc owing to the ultra-fast transfer of intramolecular charge.