Abstract
Two dimensional (2D) chromophore, 9-Hexyl-3,6-di (2’-(6-hydroxy hexyl)sulfonylphenyl)-1’-ethenyl)-9H-carbazole(Cz2PhSO2OH), and one dimensional (1D) chromophore 4-N,N-Bis(2- hydroxy ethylene) amine-4’- nitroazobenzene (DR19) with two reactive site proceeded sol-gel process were studied to compare the effects between dimension of chromophore and nonlinear optical (NLO)stability. Hybrid NLO film with another 2D chromophore,9-Hexyl-3,6-di(2’-(6-hexyl)sulfonylphenyl)-1’-ethenyl) -9H– carbazole (Cz2PhSO26C),was studied to compare the influence between physical and chemical bonding. The results show that due to the reinforcement of SiO2 polymeric structure, hybrid NLO films with covalent-bonded 2D chromophore were highly improved in temporal and thermal dynamic stability. There is no decay in second harmonic coefficient (d33) at 100℃ for 200 hr. Effective transition temperature (T0) was raised with the enhancement of temperature and time by means of increasing degree of cross-linking, though d33 owns an optimal value. Moreover, by controlling the poling condition, the degree of cross-linking of SiO2 matrix with 2D and 1D chromophore is identical. As for thermal dynamic stability, NLO films with 2D chromophore (T0 = 110℃) are obviously better than with 1D chromophore (T0 = 80℃). As for temporal stability, effective second order harmonic coefficient (deff) of NLO film with 2D chromophore (65%) is better than with 1D chromophore (30%) under individual effective transition Temperature. For hybrid NLO film, the 2D chromophore would be sublimed during poling process since no chemical bondings between chromophore and matrix.