He Wei, Yurkevich Igor V, Canham Leigh T, Loni Armando, Kaplan Andrey
Opt Express. 2014 Nov 3;22(22):27123-35. doi: 10.1364/OE.22.027123.
We develop an analytical model based on the WKB approach to evaluate the experimental results of the femtosecond pump-probe measurements of the transmittance and reflectance obtained on thin membranes of porous silicon. The model allows us to retrieve a pump-induced nonuniform complex dielectric function change along the membrane depth. We show that the model fitting to the experimental data requires a minimal number of fitting parameters while still complying with the restriction imposed by the Kramers-Kronig relation. The developed model has a broad range of applications for experimental data analysis and practical implementation in the design of devices involving a spatially nonuniform dielectric function, such as in biosensing, wave-guiding, solar energy harvesting, photonics and electro-optical devices.
我们基于WKB方法开发了一个分析模型，以评估在多孔硅薄膜上进行的飞秒泵浦-探测测量所得到的透过率和反射率的实验结果。该模型使我们能够沿着薄膜深度获取泵浦诱导的非均匀复介电函数变化。我们表明，对实验数据进行模型拟合时，所需的拟合参数数量最少，同时仍符合克莱默斯-克勒尼希关系所施加的限制。所开发的模型在涉及空间非均匀介电函数的器件设计（如生物传感、波导、太阳能收集、光子学和电光器件）的实验数据分析和实际应用中具有广泛的用途。
