Objectives, light microscopy

Light microscopy is of great importance for basic research, analysis in materials science and for the practical control of fabrication steps. Wlien used conventionally it serves to reveal structures of objects which are otherwise mvisible to the eye or magnifying glass, such as micrometre-sized structures of microelectronic devices on silicon wafers. The lateral resolution of the teclmique is detennined by the wavelength of tire light... 

Light microscopy allows, in comparison to other microscopic methods, quick, contact-free and non-destmctive access to the stmctures of materials, their surfaces and to dimensions and details of objects in the lateral size range down to about 0.2 pm. A variety of microscopes with different imaging and illumination systems has been constmcted and is conunercially available in order to satisfy special requirements. These include stereo, darkfield, polarization, phase contrast and fluorescence microscopes. 

Polarized light microscopy is the study of the microstructures of objects using their interactions with polarized light [1,2,23-27,31-33]. The method is widely applicable to polymers [34] and to liquid crystals [34-37]. The polarizing micro-... 

A more sophisticated approach uses a stack of serial sections. Three-dimensional images in all forms of light microscopy are built up as serial sections. That is, the microscope (or other device) is focused at different depths through an object, and the resulting stack of images rendered as a three-dimensional object. This technique was introduced into Raman microscopy... 

Once the sample was prepared, meristems were scored with light microscopy using the x40 objective, and the mitotic index was estimated by counting up a total number of 1000 cells in three slides of the same sample. 

ZOpT can be used to study both self-similar and self-affine fractal objects. The data at low frequencies (u and v <10) is not to be included in the calculation of D j. Figure 17.25 from Tang and Marangoni (2006) illustrates how Df, and ZOpT are calculated from the double logarithmic plot ofX vs. Y for polarized light microscopy images of the fat crystal networks. 

Advances in light microscopy have allowed the magnification of objects up to 1,000 times their original size and improved the resolution of the human eye from 0.1 mm to 0.2 Xm (see Table 1 for a comparison of the different visualization techniques). With the aid of histochemical, fluorescence, and autoradiographic methods, in particular, the use of light microscopy in the biological sciences has revealed the substructure of tissues and dynamic processes within cells. 

Figure 1.16 Engraved markings on the barrel of an objective lens. (Reproduced with permission from D.B. Murphy, Fundamentals of Light Microscopy and Electronic Imaging, Wiley-Liss. 2001 John Wiley Sons Inc.)...

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