Abbe’s theory

It should be pointed out that the theoretical optical limits of resolution predicted by Abbe s theory probably saved many other microscope manufacturers from striving after the unattainable. This may also have unwittingly contributed to the belief that was common in Europe around 1890, that physical science was largely complete, and that all of the major discoveries had already been made a belief no doubt shattered within a few years by a succession of unexpected discoveries of the greatest importance—discoveries such as radioactivity, the electron, X rays, etc., already discussed in the preceding sections of this book. 

The concept of degree of coherence is of great utility in the description of illumination conditions. Our starting point for this analysis is Abbe s theory of microscope imaging, which is applicable to optical lithographic imaging with coherent or... 

Phase Contrast. Based on Abbe s theory the Dutch physicist Frits Zernike (Nobel prize in 1953) developed phase contrast imaging in 1935, to convert the invisible phase shift within the specimen into recognizable contrast 19). A phase plate located in the lens modifies the phase and amplitude of the direct (iluminating) wave in such a way that a phase shift of A/2 is obtained (Fig. 5). The... 

Eor optical microscopy, the most significant advantage of TERS is its high spatial resolution beyond the diffraction limit of light An optical field is spatially confined into a region several tens of nanometers in size at the tip of the metalUc probe [55, 56], On the other hand, according to Abbe s theory, the minimum size A that can be resolved by a conventional optical microscope is given by [57]... 

Theory The initial understanding of the refraction of light dates back to Maxwell s study of electromagnetic radiation. Ernst Abbe invented the first commercial refractometer in 1889 and many refractometers still use essentially the same design. 

Priestley noticed that sulphur dioxide and ammonia gas are taken up by charcoal over mercury, and says the air had only been, as it were, condensed on its surface , a theory later adopted by Faraday (see Vol. IV). The effect was independently discovered by the Abbe Fontana, and he communicated his results to Priestley who in 1779 said The absorption of all kinds of air by charcoal is a capital discovery of the Abbe Fontana, which he has been so obliging as to give me leave to mention. Fontana published his experiments in 1782. In 1784 Fontana says of mes experiences sur le charbon , that Je les ai faites des les premiers terns de mon sejour a Paris , and in 1779 that he worked in Paris in 1777-8. Ostwald says Fontana was the first to describe the experiment of quenching a piece of red-hot charcoal in mercury and passing it into a tube of gas over mercury, when the gas is taken up and the mercury rises in the tube. Kopp dates Fontana s discovery in 1777, a date generally given. Scheele had published the discovery in 1777 (see p. 231). Priestley s words imply that Fontana s work was unpublished in 1779. 

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