Preparation of Two Carbazole Derivatives and its Third-Order Nonlinear Optical Properties

Abstract

Carbazole derivative is one sort of important nonlinear optical materials. In this work, new symmetric-type D-π-D carbazole derivatives, 3, 6 - di- substituted carbazole chromophores with two styryl bridges of the two-dimensional conjugated D-π-D system were synthesized via Witting reaction and characterized by IR, NMR and MS. The third-order nonlinear optical properties of the material were investigated using single-beam Z-scan technique with Sapphire femtosecond laser pulses at 800nm, repetition rate of 1 KHz and pulse width of 140fs. The results of Z-scan with and without an aperture showed that larger third-order nonlinear optical polarizabilities γ can be readily obtained in such carbazole chromophores because of the incorporation with two styryl bridges, increasing of conformational planarity and molecular conjugation length.