Using 3-aminopropyltriethoxy-silane(KH550) and 3-glycidoxypropltrimethoxy-silane(KH560) as precursors

Disperse Orange 3 (DO3) was doped into above sol and ormocer in 3wt% concentration

and the sol-gel derived films with 4μm thickness coated on ITO film were fabricated. Corona poling was performed by applying a high voltage of + 5kV to a needle electrode. After corona poling of the film at 185° for 4 hours

about 1/5 of DO3 molecules remained in solid state film

estimating from their spectra

and the concentration of DO3 molecule in poled film was estimated about 1.6×10

19

cm

-3

. Second harmonic generation (SHG) was used to probe the size and stability of the orientational order of the poled films. The second harmonic intensity of the films was measured using p (parallel polarized) excitation and p detection

and compared with that generated by a

y

-cut quartz crystal. No Maker fringe pattern for the film was observed

we could assume that the coherence length was much larger than the film thickness. The SHG intensity increases with increasing angle and reaches to maximum at θ=52°. The effective second order nonlinear coefficient

d

eff

and d

33

were estimated about 0.11pm/V and 0.14pm/V

respectively

and the intensity of SHG decreased slightly and remained ～80% of the initial value even after poling 500 hours. It is thought that for a combination of DO3 and organic inorganic gel the pore shrinkage and high baking temperature stabilize the nonlinearity in particular. Furthermore

due to leading KH550 (containing-NH

2

group) into sol-gel derived matrix

it is expected that the hydrogen bonds between DO3 and KH550 in matrix are formed and the more density of matrix is reached

which can keep the oriented DO3 stable.