Digital holographic microscopy (DHM) is an effective method that can be used to investigate transparent objects. The technique allows to get both intensity and phase distributions of wavefronts transmitted through samples without scanning or destructing them. In this paper, a DHM setup with sub-micrometer resolution is used to record the deformation of hydrogels during the swelling and shrinking process. To overcome the out-of-focus imaging caused by the shifting and deformation of the samples, numerical focusing instead of mechanical focusing is employed. The intensity images at different depths can be reconstructed by using one single hologram, and the phase change as a function of the time can be also determined.

Date Published: 27 May 2011
PDF: 7 pages
Proc. SPIE 8082, Optical Measurement Systems for Industrial Inspection VII, 80822F (27 May 2011); doi: 10.1117/12.889494

Published in SPIE Proceedings Vol. 8082:
Optical Measurement Systems for Industrial Inspection VII
Peter H. Lehmann; Wolfgang Osten; Kay Gastinger, Editor(s)