Sentis Matthias P L, Onofri Fabrice R A, Lamadie Fabrice
Opt Express. 2017 Jan 23;25(2):867-873. doi: 10.1364/OE.25.000867.
A new and computationally efficient approach is proposed for determining the refractive index of spherical and transparent particles, in addition to their size and 3D position, using digital in-line holography. The method is based on the localization of the maximum intensity position of the photonic jet with respect to the particle center retrieved from the back propagation of recorded holograms. Rigorous electromagnetic calculations and experimental results demonstrate that for liquid-liquid systems and droplets with a radius > 30µm, a refractive index measurement with a resolution inferior to 4 × 10 is achievable, revealing a significant potential for the use of this method to investigate multiphase flows. The resolution for solid or liquid particles in gas is expected to be lower but sufficient for the recognition of particle material.
提出了一种新的、计算效率高的方法，用于利用数字同轴全息术确定球形透明颗粒的折射率及其尺寸和三维位置。该方法基于从记录全息图的反向传播中获取的光子射流相对于颗粒中心的最大强度位置的定位。严格的电磁计算和实验结果表明，对于液-液系统和半径大于30μm的液滴，折射率测量分辨率可达4×10，这表明该方法在研究多相流方面具有巨大潜力。对于气体中的固体或液体颗粒，分辨率预计会更低，但足以识别颗粒材料。
