Phase Contrast


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Phase Contrast

 

a method of producing images of microscopic objects whose structural elements have refractive indexes and optical absorptivities that differ by such small amounts that the elements are indistinguishable in other methods of observing and producing images in a microscope. However, such structural elements introduce light-wave phase shifts that may differ appreciably from one another, producing variations in phase that cannot be detected by either the eye or a photographic emulsion.

Phase contrast consists in the conversion of the phase variations, by means of an optical accessory, into variations in the intensities—that is, in the amplitudes—of the light waves. Such amplitude variations can be detected by a photodetector. Phase contrast was developed by F. Zernike in 1935. (SeeMICROSCOPE: Methods of illumination and observation [microscopy].)

REFERENCES

See references under MICROSCOPE.
References in periodicals archive ?
Bt colonies were suspended in sterile distilled water as a wet mount and examined with phase contrast microscope (100X oil immersion objective) for the presence of parasporal crystals.
The framework takes phase contrast microscopy image sequences as input, and automatically outputs localized subregions in the sequences where mitosis occurred.
There is another way to estimate the energy loss using AFM, which uses the phase contrast images.
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Due to the phase contrast imaging principle [3], phase contrast microscopic images [1, 4, 5] contain artifacts, that is, bright-halo and shade-off.
Focusing on physics and hardware configurations rather than algorithms and software, they consider absorption-based X-ray imaging, X-ray phase contrast imaging, photoacoustic imaging and tomography, diffuse optical imaging, acoustical imaging, multimodality imaging, and three-dimensional in vivo microscopy.
Usefulness of phase contrast cine mode magnetic resonance imaging for surgical decision making in patients with hydrocephalus combined with achondroplasia.
Shoemaker's treatment protocol is available to everyone on line who takes the phase contrast eye test.
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In this study, we describe differential phase contrast scanning as a means of achieving quadrature detection of proteins on a spinning disc.
This visualization has been achieved by developing a sample chamber for phase contrast X-ray CT device.
These features make the unit suited for applications with low light, i.e., fluorescence, phase contrast, and darkfield microscopy.