Photophysical and nonlinear optical properties of an azobenzene substituted zinc phthalocyanine

Photophysical property and third-order optical nonlinearity of an azobenzene substituted zinc phthalocyanine (azo-ZnPc) in chloroform solution were studied by UV–Vis spectra method and a picosecond Z-scan technique at 532 nm with pulse duration of 25 ps, respectively. It was found that the azo-ZnPc shows large positive nonlinear refraction and positive nonlinear absorption, exhibiting the defocusing effect and reverse saturable absorption, respectively. The molecular second hyperpolarizability of the azo-ZnPc dyad was measured to be 3.9 × 10−30 esu. All the results suggest that the studied azo-ZnPc dyad may have potential applications in the field of nonlinear optics.