The third-order nonlinear optical properties of charge flowable trimethine cyanine with quinolone groups

Organic molecules with charge flow abilities gain much attention in third-order nonlinear optical materials. To evaluate the hypothesis of terminal donor and/or acceptor groups participating organic resonance structures for third-order nonlinear optical materials, conjugated double bonds structures with terminal amino groups are selected in this paper. The trimethine cyanine dye with quinolone skeleton (3a) was synthesized, it shows strong reverse saturable absorption and nonlinear refraction in dimethyl formamide solution at 532 nm. Then, its derivative compound (3b) with long alkyl chains was synthesized in order to improve the film forming performance, the spinning coating thin film exhibits strong reverse saturable absorption with the third-order nonlinear susceptibilities χI(3)=3.42×10^-8esu and χ( ³⁾=3.23×10^-9esu under nanosecond and picosecond laser beams respectively. The results validate that the organic compounds with terminal donor and/or acceptor groups participating resonance structures have potential value for the design of the third-order nonlinear optical materials.