Editing Microscopy (section)

== Digital holographic microscopy ==
[[File:Phase-Phase Contrast.jpg|thumb|Human cells imaged by DHM phase shift (left) and [[phase contrast microscopy]] (right)]]
{{Main|Digital holographic microscopy}}
In [[digital holographic microscopy]] (DHM), interfering [[wave front]]s from a [[coherent light|coherent]] (monochromatic) light-source are recorded on a sensor. The image is digitally reconstructed by a computer from the recorded [[hologram]]. Besides the ordinary bright field image, a [[phase (waves)|phase shift]] image is created.

DHM can operate both in reflection and transmission mode. In reflection mode, the phase shift image provides a relative distance measurement and thus represents a [[topography]] map of the reflecting surface. In transmission mode, the phase shift image provides a label-free quantitative measurement of the optical thickness of the specimen. Phase shift images of biological cells are very similar to images of stained cells and have successfully been analyzed by [[high-content screening|high content analysis]] software.

A unique feature of DHM is the ability to adjust focus after the image is recorded, since all focus planes are recorded simultaneously by the hologram. This feature makes it possible to image moving particles in a volume or to rapidly scan a surface. Another attractive feature is The ability of DHM to use low cost optics by correcting optical aberrations by software.