Performance Improvement of Digital Holographic Particle Measurement by Suppression of Speckle-like Noise and Particle Image Elongation in Depth Direction

Performance Improvement of Digital Holographic Particle Measurement by Suppression of Speckle-like Noise and Particle Image Elongation in Depth Direction Masatsugu MURAYAMA, Shigeru MURATA and Yohsuke TANAKA ABSTRACT In this paper, we show that the performance of digital holographic particle measurement is improved by suppressing speckle-like noise and particle image elongation in the depth direction. We use a deconvolution method to reduce the speckle-like noise in the background by reconstructing the image while excluding background light and shortening the particle image elongation in the depth direction. First, we compare the number of detected particles and detection accuracy between the proposed and conventional methods in numerical experiment to evaluate the performance of the present method. Then we verify the feasibility of the present method in real flow measurement by confirming that the movement of the particles in 3D space is successfully captured in observation experiments.