LARGE 2ND-ORDER OPTICAL NONLINEARITY IN A MOLECULAR-CRYSTAL FORMED FROM A CHIRAL SMECTIC LIQUID-CRYSTAL

A new approach to achieving a large second-order nonlinear optical sus ceptibility in a chiral liquid crystal is described. This approach use s an aligned smectic-C liquid crystal as a template for forming a mol ecular crystal, which freezes out the rotation of the molecular dipole s and thereby greatly enhances the noncentrosymmetric order of the str ucture. Analysis of the measured second harmonic generation gives maxi mum values of individual susceptibility components of similar to 25 pm /V, which are stable when the held is removed. (C) 1998 American Insti tute of Physics.