p-HPcCo和p-HPcZn的非线性光学性质研究

采用皮秒Z-扫描技术研究了两种不同中心金属取代的酞菁配合物2,9,16,23-四-(对羧基苯氧基)酞菁钴(p-HPcCo)和2,9,16,23-四-(对羧基苯氧基)酞菁锌(p-HPcZn)的非线性光学性质,并从离域电子共轭结构理论和共振、非共振增强理论进行了分析.结果表明:吸电子能力强的金属离子Zn2+ 取代的p-HPcZn的吸收带相对于Co2+ 取代的p-HPcCo略有红移|两种样品均具有正的三阶非线性极化率,共振增强使得p-HPcZn和p-HPcCo的三阶非线性极化率在532 nm条件下比1 064 nm条件下增强了近两个量级,中心金属离子强的吸电子能力使得p-HPcZn的三阶非线性极化率大于p-HPcCo,并在532 nm激发时,χ(3) 具有最大值1.76×10-10 esu.

Nonlinear Optical Properties of p-HpcCo and p-HPcZn

The nonlinear optical properties of two kinds of metallophthalocyanines with different central ions,2,9,16,23-tetra(p-carboxyphenyloxy) phthalocyanine cobalt (p-HPcCo) and 2,9,16,23-tetra(p-carboxyphenyloxy) phthalocyanine zinc (p-HPcZn),are investigated mainly by UV-VIS-NIR spectroscopy and picosecond Z-scan technique with 532 nm and 1 064 nm excitation.The optical properties of these two compounds are discussed using the theories of л-electron conjugated structures and resonant/non-resonant enhancement,respectively.The obtained results demonstrate that the stronger ability of the central ion to attract electron,the larger absorption band shifts towards long wavelength.Both the two metallophthalocyanines have positive third-order nonlinear susceptibilities.Under the excitation of wavelength of 532 nm close to the resonance field,the third-order nonlinear susceptibility χ(3) of p-HPcZn and p-HpcCo is almost two-order of magnitude larger than at 1 064 nm.With the stronger ability of the central ion to attract electron,the third-order nonlinear susceptibility χ(3) of p-HPcZn is larger than p-HpcCo,and shows a maximum value,1.76×10-10 esu,under the excitation of wavelength of 532 nm.