Holographic Microscopy

Holographic microscopy is the most common form of quanti­tative phase imaging. The HoloMonitor^® live cell imaging microscope employs digital holographic micro­scopy to allow non-invasive visualization and quanti­fication of living cells without compro­mising cell integrity.

Conventional Holography

A traditional hologram is recorded on a photo­graphic plate. The holographic image is created by illuminating the developed holo­gram with the laser that was used to create the hologram. This recreates the same light wavefield that originally came from the imaged object. The object appears to be 3-dimensional as each eye image a slightly different part of the wavefield, just like they would have done if the object was still there.

Digital Holography

The advent of high-resolution image sensors has made it possible to instead record a hologram digitally, allowing the holo­graphic image to be created by a computer, rather than re-illuminating the developed holo­gram. The computer actually creates two images: an amplitude (intensity) and a phase image. As unstained cells are trans­parent, most of the information resides in the phase image.

The Holographic Microscopy Principle

Holographic microscopy creates (quantitative) phase images by letting a sample beam and a refer­ence beam interfere to create an interference pattern or hologram, as shown in the principle image below. The hologram is recorded by an image sensor and computer-processed to produce the final phase image.