This paper reports on a new technique of measurements of microbubble position in three dimensions with high time-resolution. The technique is based on micro digital holographic particle tracking velocimetry. In this technique, an intensity profile is constructed from a holographic image of a microbubble where the profile results in showing two peaks. The distance between the two peaks appears to relate to the size of the microbubble’s diameter. The three-dimensional position of the bubble can be detected by the center of the two peaks and the center point of the bubble image focused by a digital hologram. We also theoretically obtained the intensity profile of a microbubble by considering a refraction of light on a bubble surface to a ring-shaped aperture model. The theoretically obtained distance between the two peaks is found to be in good agreement with the values obtained experimentally.
© 2011 Optical Society of America
Original Manuscript: May 19, 2011
Revised Manuscript: July 27, 2011
Manuscript Accepted: July 27, 2011
Published: October 31, 2011
Shin-ichi Satake, Yukihiro Yonemoto, Tadashi Kikuchi, and Tomoaki Kunugi, "Detection of microbubble position by a digital hologram," Appl. Opt. 50, 5999-6005 (2011)