Second harmonic light scattering from a bent-core nematic liquid crystal*

We study the angular distribution of second harmonic (SH) light scattered from the aligned nematic phase of a bent-core liquid crystal. Throughout the nematic range and for certain combinations of polarizations of the fundamental and second harmonic fields, we detect peaks in the SH signal at non-zero scattering vectors ($\pm$q) along the nematic director, while the signal for q = 0 (forward direction) remains at the background level. The value of q, which corresponds to a length scale in the micron range, decreases with temperature when heating toward the nematic to isotropic transition. We will present a model to explain the major aspects of our results and indicate their significance in terms of the structure of bent-core nematics.