In this paper, the nonlinear refractive index of colloidal gold nanoparticles under continuous wave illumination is investigated with the z-scan technique. Gold nanoparticles were synthesized using ascorbic acid as reductant, phosphates as stabilizer and cetyltrimethylammonium chloride (CTAC) as surfactant agent. The nanoparticle size was controlled with the CTAC concentration. Experiments changing incident power and sample concentration were done. The experimental z-scan results were fitted with three models: thermal lens, aberrant thermal lens and the nonlocal model. It is shown that the nonlocal model reproduces with exceptionally good agreement; the obtained experimental behaviour.

中文翻译：

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通过抗坏血酸还原合成的金纳米粒子的非局部非线性折射率：拟合模型的比较

在本文中，胶体金纳米粒子在连续波照射下的非线性折射率是用 z 扫描技术研究的。以抗坏血酸为还原剂，磷酸盐为稳定剂，十六烷基三甲基氯化铵（CTAC）为表面活性剂，合成了金纳米粒子。纳米颗粒的大小由 CTAC 浓度控制。完成了改变入射功率和样品浓度的实验。实验 z 扫描结果符合三个模型：热透镜、异常热透镜和非局部模型。结果表明，非局部模型以非常好的一致性再现；得到的实验行为。