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Phase-contrast microscopy is particularly important in biology. It reveals many cellular structures that are invisible with a bright-field microscope, as exemplified in the figure. These structures were made visible to earlier microscopists by staining, but this required additional preparation and death of the cells. The phase-contrast ...
Phase-contrast imaging is the highest resolution imaging technique ever developed, and can allow for resolutions of less than one angstrom (less than 0.1 nanometres). It thus enables the direct viewing of columns of atoms in a crystalline material. [20] [21] The interpretation of phase-contrast images is not a straightforward task.
TEM Ray Diagram with Phase Contrast Transfer Function. Contrast transfer theory provides a quantitative method to translate the exit wavefunction to a final image. Part of the analysis is based on Fourier transforms of the electron beam wavefunction. When an electron wavefunction passes through a lens, the wavefunction goes through a Fourier ...
X-ray absorption (left) and differential phase-contrast (right) image of an in-ear headphone obtained with a grating interferometer at 60kVp. Phase-contrast X-ray imaging or phase-sensitive X-ray imaging is a general term for different technical methods that use information concerning changes in the phase of an X-ray beam that passes through an object in order to create its images.
Phase-contrast microscope, which applies the phase contrast illumination method. Epifluorescence microscope , designed for analysis of samples that include fluorophores. Confocal microscope , a widely used variant of epifluorescent illumination that uses a scanning laser to illuminate a sample for fluorescence.
This technique MIDI-STEM (matched illumination and detector interferometry-STEM), while being less common, is used with ptychography to create higher contrast phase images. The placement of a phase plate with zones of 0 and π/2 phase shift in the probe forming aperture creates a series of concentric rings in the resulting CBED pattern.
After its introduction in the 1940s, live-cell imaging rapidly became popular using phase-contrast microscopy. [11] The phase-contrast microscope was popularized through a series of time-lapse movies (see video), recorded using a photographic film camera. [12] Its inventor, Frits Zernike, was awarded the Nobel Prize in 1953. [13]
The phase telescope/Bertrand lens is inserted into the microscope in place of an eyepiece to move the intermediate image plane to a point where it can be observed. Phase telescopes are primarily used for aligning the optical components required for Köhler illumination and phase contrast microscopy. For Köhler illumination the light source and ...