Koehler illumination advantages for imaging in TEM
| Autor: | J. L. Lehman, W. Probst, Gerd Benner, R. Bauer |
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| Rok vydání: | 1991 |
| Předmět: | |
| Zdroj: | Proceedings, annual meeting, Electron Microscopy Society of America. 49:1010-1011 |
| ISSN: | 2690-1315 0424-8201 |
| DOI: | 10.1017/s0424820100089366 |
| Popis: | The Koehler principle of correct illumination in the light microscope was described about 100 years ago by A. Koehler. It is used in most of todays upper class light microscopes in order to achieve optimal imaging conditiones. Basically, in light microscopy (LM) and electron microscopy (EM) the same optical principles are used in order to describe or design beam paths in the different types of instruments. Mainly due to technical reasons up to now it was, however, not possible to transfer all the advantageous optical experience from LM to EM. The EM 910 from Carl Zeiss is now the first TEM providing the benefits of Koehler illumination.The Koehler principle is the most favourable design of the illumination beam path of a microscope as an imaging beam path for the source. In the first step the light source (LM) or the electron beam crossover (TEM) is imaged into the front focal plane of the condenser lens (LM) or the objective-prefield lens (TEM), respectively. |
| Databáze: | OpenAIRE |
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