Nonlinear optical refraction of the natural dye extract from ficus carica in PVA films and different solvents

The polar solvents such as DIW, EG, Eth, and DMSO nonlinear optical (NLO) response of natural dye extracted from Ficus carica are investigated via a z-scan technique at λ = 532 nm at a laser power of 6 mW. The dye is doped with poly(vinyl alcohol) film and dissolved in different solvents. The dye's optical characteristics are tuned with different solvents and dopant concentrations. The sample showed a negative nonlinear refractive index n2 with order of 10−7 in polar solvents ascribed to thermal effect. Self-diffraction rings may occur owing to the thermal characteristics of the nonlinear refractive (NLR) index. A spatial self-phase modulation technique is used to investigate the diffraction rings. The study also examines the optical limiting performance of the FC dye at different polar solvents. The nonlinear optical metrics, cost-effectiveness, and environmental sustainability suggest the green dye has promising potential as an optical limiter.