Electro-optic effects in two tolane side-chain nonlinear-optical polymers: comparison between measured coefficients and second-harmonic generation

Abstract

The electro-optic coefficients for the chromophore nitroamino tolane [NAT:HOCH2CH2-N(C2H5)-ϕ-C≡ C-ϕ-NO2] attached to either a poly(methyl methacrylate) or an epoxy polymer have been measured by three different techniques: attenuated total reflection, ellipsometric reflection, and Mach–Zehnder interferometry. All the results for r33 and r13 were consistent and in agreement. A comparison of these experimental methods is given. The ratios between the electro-optic coefficients and the relationships between the coefficients and the second-harmonic components give additional information about these nonlinear-optical polymers. Interestingly, it was found that the observed electro-optic coefficients increased after the samples had aged a few months.