Digital in-line holographic microscopy has a strong potential in measuring various three-dimensional (3D) microscale flow phenomena. However, the axial elongation problem in reconstructing particles severely degrades the measurement accuracy along the light propagation direction. In this Letter, we utilize the lenslike characteristic of tens of micrometers size transparent spherical particles to extract their 3D position. A sharp intensity peak is observed in the reconstructed wave field, resulting from the light-focusing effect of the particle. As a result, the depth-of-focus constraint caused by the particle size is eliminated and the measurement accuracy is drastically improved up to submicrometer resolution.
© 2011 Optical Society of America
Original Manuscript: August 9, 2011
Revised Manuscript: September 27, 2011
Manuscript Accepted: September 27, 2011
Published: October 19, 2011
Vol. 7, Iss. 1 Virtual Journal for Biomedical Optics
Yong-Seok Choi and Sang-Joon Lee, "High-accuracy three-dimensional position measurement of tens of micrometers size transparent microspheres using digital in-line holographic microscopy," Opt. Lett. 36, 4167-4169 (2011)