A new type of organic donor-π-acceptor compounds with third-order nonlinear optical properties

Ten new organic donor-pi-acceptor compounds were synthesized and characterized by UV, IR, H-1 NMR and elemental analysis. Off-resonant third-order nonlinear optical properties of the compounds were measured using femtosecond laser and degenerate four-wave mixing technique. The third-order nonlinear optical susceptibilities chi((3)) were 3.50-4.29 x 10(-13) esu. The nonlinear refractive indexes n(2) were 6.42-7.89 x 10(-12) esu. The second-order hyperpolarizabilities gamma of the molecules were 3.63-4.47 x 10(-31) esu. The response times were 69-112 fs. The results show that these compounds have potential nonlinear optical applications. (C) 2008 Elsevier B.V. All rights reserved.