Second-order nonlinearity in bulk azodye-doped hybrid inorganic–organic materials by nonresonant all-optical poling

Azodye-doped vinyl group substituted bulk silica materials were prepared by a sol–gel method. Photoinduced noncentrosymmetry in these initially centrosymmetric rigid matrixes was demonstrated first using nonresonant all-optical poling with a fundamental light at wavelength of 1500 nm and its second-harmonic light. The largest photoinduced second-order nonlinear optical coefficient d33 was estimated to be 8×10−3 pm/V. The characteristic kinetics of decay of the induced second-order susceptibility was measured by second-harmonic generation. Although the signal decay was fast and the coefficient d33 was low, we found that increasing the power of the seeding beams could improve the second-harmonic signal decay process.