| Ferroelectric Liquid Crystals (FLCs) exhibit thermodynamically stable polar order in the chiral smectic (SmC*) phase. FLCs can therefore be used as nonlinear optical (NLO) materials in many of the most interesting NLO applications, since they satisfy the symmetry requirement for non-zero second order nonlinear optical susceptibility χ2. FLCs are especially interesting in this regard, since as a class these materials are easily integrated with semiconductor chips, in principle allowing the fabrication of hybrid photonic devices not achievable using conventional ceramic NLO materials. For most second order NLO applications, polymer glasses frozen from an FLC phase, and possessing the FLC polar structure, would be preferable to the fluid phase itself. Indeed, in some applications, such as freestanding optical fibers for frequency processing, polymer glasses are required. Especially in the latter regard, main-chain FLC polymers (FLCPs) are attractive, since it is expected that the rheological properties of a the main-chain FLCP would provide a fiber with the FLC polar axis oriented normal to the fiber axis—optimum for NLO processing of light propagating in the fiber. Herein are described the synthesis and characterization of FLCPs designed for NLO applications, demonstrating the correctness of these expectations. |
