Gao Jian, Guildenbecher Daniel R, Engvall Luke, Reu Phillip L, Chen Jun
Appl Opt. 2014 Sep 20;53(27):G130-8. doi: 10.1364/AO.53.00G130.
Digital in-line holography provides simultaneous particle size and three-dimensional position measurements. In general, the measurement accuracy varies locally, and tends to decrease where particles are closely spaced, due to noise resulting from diffraction by adjacent particles. Aggravating the situation is the identification of transversely adjoining particles as a single particle, which introduces significant errors in both size and position measurements. Here, we develop a refinement procedure that distinguishes such erroneous particles from accurately detected ones and further separates individual particles. Effectiveness of the refinement is characterized using simulations, experimental holograms of calibration fields, and a few practical applications to liquid breakup. Significant improvements in the accuracy of the measured particle sizes, positions, and displacements confirm the usefulness of the proposed method.
数字同轴全息术可同时测量颗粒大小和三维位置。一般来说，测量精度在局部会有所变化，并且由于相邻颗粒的衍射产生的噪声，在颗粒间距较小的地方精度往往会降低。更糟糕的是，将横向相邻的颗粒识别为单个颗粒，这会在尺寸和位置测量中引入重大误差。在此，我们开发了一种细化程序，可将此类错误识别的颗粒与准确检测到的颗粒区分开来，并进一步分离单个颗粒。使用模拟、校准场的实验全息图以及一些液体破碎的实际应用来表征细化的有效性。测量的颗粒大小、位置和位移精度的显著提高证实了该方法的实用性。
