Non-linear optical properties of metallorganic ferroelectric liquid crystals

Second harmonic generation (SHG) efficiencies d(eff) were determined for Pt-containing ferroelectric liquid crystals (FLCs). A relatively simple method is presented which allows for the simultaneous determination of the second order susceptibility tensor coefficients d(ij) together with the dispersion and birefringence at the fundamental frequency. The relation between the d(ij) coefficients is qualitatively interpreted in terms of the molecular shape and of a scheme proposed for the molecular orientation in the ferroelectric phase. Contrary to the usual situation with calamities, d(23) is much higher than the rest of the coefficients. This peculiarity, which reflects the 3D character of the molecular response, is interesting since d(23) is directly involved in d(eff) for phase matched SHG.