STRONGLY NONLINEAR-OPTICAL FERROELECTRIC LIQUID-CRYSTALS FOR FREQUENCY-DOUBLING

From our research for novel non-linear optical (NLO) materials for fre quency doublers and optical modulators we report on new ferroelectric liquid crystals, which for the first time, exhibit second order NLO co efficients (for example d22 = 5 pm V-1, which are comparable to those of state of the art inorganic NLO materials. The novel compounds conta in 5-amino-2-nitrophenyl groups attached close to the chiral centres. The switching behaviour of the new compounds, their spontaneous polari zation, as well as their frequency doubling of Nd:YAG laser pulses in the S(C) and in the glass state, are reported. Moreover their wavegui ding properties are presented.