Weaning away from the present microscopes, we have the newest of inventions and it is the Portable Lens-Free Holographic Microscope. This new lens-free microscopy technique uses cheap, small and a portable device that enables wide-field screening of pathology slides.
Functioning of Hollographic Microscopy:
The Lens-Free Holographic Microscope generates a holographically reconstructed image. The objects within this image can be brought to focus at any depth after the image capture. This new age microscope does not require and mechanical components and makes image capturing almost automatic.
Existing Digital Holographic Microscopy:
These microscopes are unique in a way. They do not record the projected image of an object. What actually happens is that the light wave front information from the object is recorded as a hologram, digitally. The computer then calculates the object's image from the hologram using a numerical reconstruction algorithm. Hence, a computer algorithm replaces the traditional image forming lens.
Other variants of digital holographic microscopy include interferometric microscopy, optical coherence tomography and the diffraction phase microscopy. In order to obtain amplitude and phase information, reference wave front is used and this is common to all methods of microscopy. A digital image sensor or a photo detector records the image of an object which is formed by a computer. In this method, the essential information is lost and only the intensity information is recorded. This becomes the disadvantage of earlier digital holographic microscopy variants.
Digital holography is mainly applied to light microscopy and electron microscopy. Dennis Gabor developed holography so as to improve the existing electron microscope.