|
Phase retrieval holography can suppress twin image problem of Gabor holography which causes blurred objects at a reconstructed focus position. We compared three-dimensional trajectories of spray droplets between conventional Gabor holography and developed phase retrieval holography under the high-speed imaging conditions to confirm the suppression of the twin image problem. Droplets sprayed from a nebulizer (Panasonic, EW-KA30- W) have an average diameter of 40.0 μm, mean velocity of 0.65 m/sec and Reynolds number of 0.2, respectively. Two holograms using phase retrieval holography were recorded two high-speed cameras (FASTCAM Mini UX100, Photron, frame rate: 4000 fps). It is found that phase retrieval holography has denser trajectories than Gabor holography because of suppressing the twin image problem. Additionally, number of the detected points of phase retrieval holography is almost 20 times higher than that of Gabor holography at each time step.
|
