Interferometric spectroscopy of scattered light can quantify the statistics of subdiffractional refractive-index fluctuations.
Interferometric spectroscopy of scattered light can quantify the statistics of subdiffractional refractive-index fluctuations.
复制标题
散射光的干涉测量光谱可以量化亚分离折射率波动的统计数据。
DOI：
10.1103/physrevlett.111.033903
复制
发表时间：
2013-07-19
影响因子：
8.6
通讯作者：
Backman V
中科院分区：
文献类型：
--
作者：
Cherkezyan L;Capoglu I;Subramanian H;Rogers JD;Damania D;Taflove A;Backman V
尽管在物理学、生物学和其他科学中具有重要意义，但由于分辨率的基本衍射极限，远区纳米级结构的光学传感仍然是一个悬而未决的问题。我们确定，远场衍射限制显微镜图像的光谱方差预期值 (Σ̃2) 可以量化无标记、弱散射样品在亚衍射长度尺度上的折射率波动。我们报告了任意折射率分布的 Σ̃ 的一般表达式。对于指数折射率空间相关性，我们获得了 Σ̃ 的封闭式解，该解与麦克斯韦方程组的三维有限差分时域解非常一致。在纳米尺度上传感复杂的非均匀介质可以使从材料科学到医学诊断等领域受益。
Despite major importance in physics, biology, and other sciences, optical sensing of nanoscale structures in the far-zone remains an open problem due to the fundamental diffraction limit of resolution. We establish that the expected value of spectral variance (Σ̃2) of a far-field, diffraction-limited microscope image can quantify the refractive-index fluctuations of a label-free, weakly scattering sample at subdiffraction length scales. We report the general expression of Σ̃ for an arbitrary refractive-index distribution. For an exponential refractive-index spatial correlation, we obtain a closed-form solution of Σ̃ which is in excellent agreement with three-dimensional finite-difference time-domain solutions of Maxwell's equations. Sensing complex inhomogeneous media at the nanoscale can benefit fields from material science to medical diagnostics.