Short coherence digital holography for 3D microscopy

An optical system based on short coherence digital holography suitable for 3D microscopic investigations is described. An interferometer is built by u sing a short coherence laser (coherence length 50 micrometers). The sample is located in one arm of the interferometer, and the other arm is used as r eference. The interference occurs only when the path lengths of the referen ce and measurement arms are matched within the coherence length of the lase r. This interference pattern (hologram) is recorded on a CCD faceplate. The reference mirror position is shifted and, a sequence of holograms is recor ded. These are then reconstructed numerically by using the wave propagation relation. The reconstruction contains the 3D information of the object. Ex perimental results showing the difference between a white light image and a short coherence hologram are presented.