Spring 2011: Independent  Research   

In traditional holography, a coherent light source is split into two beams.  One of the beams shines onto the object of interest, causing light to reflect.  The other is interfered with the reflected beam to cause an interference pattern.  Reconstructing that interference pattern results in an image of the original object, but with depth.  That is to say, looking at the picture from different angles shows different angles of the object.  For a more in-depth discussion of holography, visit the wikipdia page: http://en.wikipedia.org/wiki/Hologram.

With digital holographic microscopy the reconstruction is completed electronically.  In this particular case, the interference is “in-line,” which means that the reflected and interfering waves are sent along the same path.  The image that the camera takes is the hologram.  It has interference rings that can then be digitally reconstructed to show a picture of what is actually happening at different depths.  For videos showing sample reconstructions, click the super resolution microscope link below.  For a theoretical discussion of digital holographic principles see http://web.mit.edu/optics/www/dhi.htm.

Click the images below for more information on the two types of holographic microscopes created.