Third-order optical nonlinearities of asymmetric texaphyrins and their application in optical limiting

Summary form only given. The title compounds, asymmetric tripyrrane-containing 22/spl pi/ electrons pentaazadentate aromatic macrocyclic metal complexes, which have zero phonon line appearing on near IR region /spl lambda//sub max/ 760nm, were synthesized by an improved procedure. The nonlinear excited state absorptions at 532nm in the cadmium texaphyrin solution have been studied using 8ns and 23ps laser pules. Third-order nonlinear optical susceptibilities for the solutions of two asymmetric porphyrin-like metal complexes in methanol at 1064nm were measured by the degenerate four wave mixing frequency and obtained the off-resonant third-order hyperpolarizabilities as 1.2 x 10/sup -31/ esu and 1. 5 x 10/sup -31/ esu for asymmetric cadmium and gadoliaium texaphyrin respectively. The optical limiting of CW laser through thermal self-defoucsing and reverse saturable absorption for the title compounds have been demonstrated and an improved optical limiter was showed.