Research on nonlinear optical limiting of two-dimensional materials suspensions

Abstract

The selection of appropriate solutes and solvents for optimizing the nonlinear optical limiting (NOL) performance of suspensions poses significant challenges in nonlinear optics research. In this paper, we systematically design twelve novel suspensions of two-dimensional materials by selecting three typical solutes—graphene, molybdenum disulfide (MoS₂), and tungsten disulfide (WS₂)—combined with four solvents: distilled water, ethanol, carbon disulfide (CS₂), and carbon tetrachloride (CCl₄). Among these solvents, distilled water and ethanol are commonly used solvents for NOL, while CS₂ and CCl₄ are specifically chosen for their advantageous properties, such as low boiling points and optimal surface tension. We perform NOL experiments on each suspension separately and find that the MoS₂–CS₂ suspension exhibits the most pronounced optical limiting effect, with transmittance decreasing from 80.9% under low-intensity light to 22.9% under high-intensity light. Additionally, suspensions with distilled water and ethanol as solvents demonstrate lower limiting thresholds, while those with CS₂ and CCl₄ as solvents exhibit higher damage thresholds. The NOL mechanism of these suspensions involves both nonlinear scattering and nonlinear absorption, with nonlinear scattering being the dominant process. These findings suggest that selecting appropriate solutes and solvents in suspensions can optimize their performance for various applications, offering guidance for two-dimensional material suspensions.