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

Ten new organic donor-π-acceptor compounds were synthesized and characterized by UV, IR, 1H 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 χ(3) were 3.50-4.29 × 10−13 esu. The nonlinear refractive indexes n2 were 6.42-7.89 × 10−12 esu. The second-order hyperpolarizabilities γ of the molecules were 3.63-4.47 × 10−31 esu. The response times were 69-112 fs. The results show that these compounds have potential nonlinear optical applications.