本文研究了非线性折射率梯度流体中蜃景形成的原理. 基于菲涅耳定律建立了光路模型，在此模型基础上借助 Matlab 模拟出光路以及蜃景成像规律.配置了一种竖直方向上折射率负指数梯度变化的溶液，用激光照射该溶液得到实际光路; 借助 Tracker 软件提取光路数据点，利用 Matlab进行数据分析，实验光路函数和成像位置与菲涅耳定律预测结果一致.我们还分析了在实验中忽略掉次要因素的合理性，说明了菲涅耳定律解释蜃景形成的正确性.

 This article studies the principle of mirage formation in nonlinear index

gradient fluids. Based on Snell's law，the optical path model is established. On this basis，the

optical path and mirage imaging law are simu- lated with MATLAB. A solution with negative

exponential gradient of refractive index in the vertical direction is con- figured，and the actual

optical path is obtained by irradiating the solution with laser. The data points of optical path

are extracted by tracker software，and the data are analyzed by MATLAB. The experimental

optical path function and imaging position are consistent with the prediction results of Snell's

law. We also analyze the rationality of neg- lecting the secondary factors in the experiment，which

shows that Snell's law is reasonable The law explains the cor- rectness of mirage formation.