Ferroelectric nematic fluids are promising materials for tunable nonlinear photonics, with applications ranging from second harmonic generation to sources of entangled photons. However, the few reported values of second-order susceptibilities vary widely depending on the molecular architecture. In a new paper in Advanced Optical Materials, Matija Lovšin, Luka Cmok, Alenka Mertelj, Irena Drevenšek-Olenik, and Nerea Sebastián, together with collaborators from the University of Leeds, have systematically measured second-order NLO susceptibilities of different materials that exhibit the ferroelectric nematic phase, as well as the more recently discovered layered smectic A ferroelectric phase. The materials investigated include archetypal molecular architectures as well as mixtures showing room-temperature ferroelectric phases. The measured values, which range from 0.3 to 20 pm V−1, are here reasonably predicted by combining calculations of molecular-level hyperpolarizabilities and a simple nematic potential, highlighting the opportunities of modelling-assisted design for enhanced NLO ferroelectric fluids.
The article, published in Advanced Optical Materials, can be found here: https://advanced.onlinelibrary.wiley.com/doi/10.1002/adom.202503018