High thermally stable hybrid nonlinear optical films containing heterocycle chromophores

Two azole heterocycle-contained chromophores, named EBTC and EBOC respectively, were synthesized and then reacted with 3-isocyannatopropyltriethoxysilane (ICTES) to form functionalized alkoxysilane dyes (ASDs) which were named as ASD-EBTC and ASD-EBOC, respectively. Sol solutions were obtained after co-hydrolysis/condensation of ASD and tetraethoxysilane (TEOS). Second-order nonlinear optical (NLO) inorganic–organic hybrid films were successfully prepared via sol–gel process. The second harmonic coefficients (d33) of poled hybrid films were measured by a Maker fringe technique. The d33 values obtained for the EBTC and EBOC films are 23.7 and 9.3 pm/V, respectively. The hybrid film containing benzothiazole exhibited better NLO properties than its analogue containing benzoxazole.