Plasmonic nanomaterials exhibit a strong light-matter interaction that can be precisely controlled by the size, shape, material composition, and alignment of nanoparticles (NPs) within a medium. When NPs are arranged in a two-dimensional array, coupling between localized surface plasmon resonance can lead to a significant enhancement of the near-field electric field intensity compared to isolated NPs. We have successfully utilized the elastic forces of nematic liquid crystals to align gold nanospheres, resulting in a notable enhancement of the third-order nonlinear optical absorption coefficient due to plasmon coupling.
Plasmon enhancement of third-order nonlinear optical absorption of gold nanoparticles dispersed in planar oriented nematic liquid crystals
Nanotechnology 34 (36), 365205 (2023)
Aligning 20nm gold nanoparticles in planar-oriented nematic liquid crystals enhances their linear and nonlinear optical absorption coefficients, showcasing the potential of liquid crystals for assembling nanoparticles with improved optical properties. Optical z-scan studies reveal a higher third-order nonlinear optical absorption coefficient for planar-oriented samples compared to planar-degenerate ones.
Polarization Z-Scan Studies Revealing Plasmon Coupling Enhancement Due to Dimer Formation of Gold Nanoparticles in Nematic Liquid Crystals
Micromachines 14 (12), 2206 (2023)
Plasmon coupling of gold nanoparticle dimers in nematic liquid crystal matrices is investigated using the polarization z-scan technique. The study reveals a 2–3-fold increase in nonlinear absorption coefficient in parallel-oriented cells when incident light polarization aligns with the rubbing direction, while twisted nematic cells show consistent enhancement across all polarization angles.
Dynamic control of third-order nonlinear absorption coefficient of gold nanoparticle/liquid crystal composites under external electric fields
Journal of Nonlinear Optical Physics & Materials 2550031 (2025)
This study investigates the dynamic control of third-order nonlinear optical absorption properties of gold nanoparticles dispersed in nematic liquid crystals. The findings illustrate the potential of AuNP/nematic LC systems for creating tunable photonic devices.
