In this paper, we derived the conditions for recording a particle using the phase retrieval method with two holograms. The distance between the two holograms affects the signal-to-noise ratio of the reconstructed hologram and the number of iterations. The calibration procedure for this misalignment was also experimentally and numerically demonstrated. The observation of the settling particles was conducted by two high-speed cameras at 4,000 fps as shown in Fig. (a). Blurred particles in Fig. (b) are reconstructed using the Gabor holography. Whereas, fringe patterns and reconstructed particles are more clearly observed using the phase retrieval method shown in Fig. (c). Therefore, we conclude that the phase retrieval method with two high-speed cameras could be used more widely in particle measurement (e.g., dispersed micro particles, plankton, snow crystals, and fuel droplets).

1. Camera layout for phase retrieval method with two cameras in digital holography
   Yohsuke TANAKA, Shunsuke TANI and Shigeru MURATA
   ICHSIP 31, Paper Number:1B-P08, Suita, Osaka, Japan, November 7-10, 2016.


2. Phase Distribution Measurement of Transparent Film Using Digital Holography with Phase Retrieval Method
   Hirotaka YAMAOKA, Yohsuke TANAKA, Shunsuke TANI and Shigeru MURATA
   ICHSIP 31, Paper Number:1B-P07, Suita, Osaka, Japan, November 7-10, 2016.


3. Phase retrieval method for holographic particle measurement with two cameras
   Yohsuke Tanaka, Shigeru Murata, Shunsuke Tani
   9th International Conference on Multiphase Flow, Paper Number:327, Firenze, Italy, May 22-27, 2016.


4. Positional adjustment of a phase retrieval holographic method for particle measurement with two cameras
   Yohsuke Tanaka, Tasuku Nakajima, Shigeru Murata
   The 9th International Symposium on Measurement Techniques for Multiphase Flows, Paper Number:B221, Sapporo, Hokkaido, Japan, July 23-25, 2015.

© Measurement System Laboratory, Kyoto Institute of Technology.