Zhang Di, Cherkezyan Lusik, Capoglu Ilker, Subramanian Hariharan, Chandler John, Thompson Sebastian, Taflove Allen, Backman Vadim
Opt Lett. 2015 Nov 1;40(21):4931-4. doi: 10.1364/OL.40.004931.
We previously established that spectroscopic microscopy can quantify subdiffraction-scale refractive index (RI) fluctuations in a label-free dielectric medium with a smooth surface. However, to study more realistic samples, such as biological cells, the effect of rough surface should be considered. In this Letter, we first report an analytical theory to synthesize microscopic images of a rough surface, validate this theory by finite-difference time-domain (FDTD) solutions of Maxwell's equations, and characterize the spectral properties of light reflected from a rough surface. Then, we report a technique to quantify the RI fluctuations beneath a rough surface and demonstrate its efficacy on FDTD-synthesized spectroscopic microscopy images, as well as experimental data obtained from biological cells.
我们之前已经确定，光谱显微镜可以在无标记且表面光滑的介电介质中对亚衍射尺度的折射率（RI）波动进行量化。然而，为了研究更实际的样品，如生物细胞，粗糙表面的影响也应予以考虑。在本信函中，我们首先报告一种用于合成粗糙表面微观图像的解析理论，通过麦克斯韦方程组的时域有限差分（FDTD）解来验证该理论，并表征从粗糙表面反射的光的光谱特性。然后，我们报告一种量化粗糙表面下方RI波动的技术，并在FDTD合成的光谱显微镜图像以及从生物细胞获得的实验数据上展示其有效性。
