Nonlinear optical limiting material: resin composed of reduced graphene oxide and methyl red

The advancement of solid-state nonlinear optical limiting (NOL) materials plays a crucial role in improving the practical applications of optical limiting technology. In this paper, we use a simple physical blending method to prepare what is, to our knowledge, a new solid-state NOL material: a reduced graphene oxide (rGO)/methyl red (MR) co-doped epoxy resin (rGO/MR-ER) film, which can be used to achieve excellent NOL effects. The optical limiting properties of rGO/MR-ER films were investigated under a fixed MR concentration of 1.07 mg/mL and varying rGO doping concentrations (0.0071, 0.0143, and 0.0214 mg/mL). The sample with an rGO concentration of 0.0071 mg/mL exhibits the strongest NOL effect, with a linear transmittance of up to 70.5% and a minimum transmittance of 39.1%. The nonlinear absorption coefficient, nonlinear refractive index, and third-order nonlinear optical susceptibility at a wavelength of 1064 nm are measured by Z-scan experiments. The results of the Z-scan experiments show that the rGO/MR-ER film has a large nonlinear absorption coefficient (6.41 ± 0.49 × 10^-8 m/W). The rGO/MR-ER films exhibit other outstanding characteristics, including ease of fabrication and environmental friendliness. The proposed rGO/MR-ER film could be an excellent NOL material for optical limiting.