Abstract <p>This study investigates the influence of citrate-capped gold nanoparticles (AuNPs) dispersed in varying concentrations within the liquid crystal compound 4-decyloxybenzoic acid (10oba) for modulation of optical properties. Incorporation of AuNPs, the liquid crystalline (LC) phases remained stable, their transition temperatures were approximately same with complementary methods. A modified spectrometer was employed to measure birefringence across multiple wavelengths, revealing a progressive increase in optical properties with higher AuNP concentrations. To evaluate the orientation ordering within the system, several theoretical models—including the Kuczynski internal field model, Vuks model, Haller’s extrapolation, and effective geometry parameter method—were applied to determine the order parameter. All theoretical models also consistently indicate an enhancement in optical properties with increasing AuNP content. This trend is attributed due to strengthened van der Waals interactions between the LC molecules and the gold nanoparticles, which promote improved molecular alignment and optical properties within the mesophase. These findings emphasize the potential of nanoparticle-doped LC systems for modulating optical properties useful for light dependent applications.</p>