Phase contrast imaging optical microscopy

The situation is somewhat comparable to positive and negative phase contrast in optical microscopy. The lens imperfections have been used to Introduce a phase shift of jt/2 in the same way as the quarter wavelength ring in the optical microscope. Only beams passing through the "window in which the condition sin X =- I is met, interfere with the required phase relationship that causes the image to represent maxima in projected potential as dark areas. 

The sample used for a demonstration of broadband TPF imaging with compressed PCF supercontinuum in Figure 7.17 was a commercially available test slide (Invitrogen FluoCells , prepard slide 1, containing labeled bovine pulmonary artery endothelial cells). The conventional optical phase-contrast microscopy image... 

In electron microscopy as in any field of optics the overall contrast is due to differential absorption of photons or particles (amplitude contrast) or diffraction phenomena (phase contrast). The method provides identification of phases and structural information on crystals, direct images of surfaces and elemental composition and distribution (see Section H below). Routine applications, however, may be hampered by complexities of image interpretation and by constraints on the type and preparation of specimens and on the environment within the microscope. 

Fig. 12. Phase-contrast optical microscopy images after mixing phosphatidyl-cholesterol based liposomes bearing the complementary guanidinium and phosphate moieties...

Figure 1.32 Optical arrangement of phase contrast microscopy. Shading marks the paths of diffracted light. (Reproduced with permission from D.B. Murphy, Fundamentals of Light Microscopy and Electronic Imaging, Wiley-Liss. 2001 John Wiley Sons Inc.)...

Optical microscopy on phase contrast mode allows observation of the different morphologies obtained for each PP/interfacial modifier/PA6 blend. By image analysis techniques, it is possible to carry out statistical field measurements not only of the mean number of particles on the dispersed phase but also of their preferential geometry, mean size, and size distribution. 

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