Reflected light microscopy

Reflected light microscope

The microscope is an instrument used in histolology and one of the main goals is to enable the microscopic structure of cells, tissues and organs. Reflected light microscopy is one of the method of light microscopy.

In reflected light microscope the light incident on the sample and is reflected so speculate. There is one half-mirror in which 50% of the light is reflected and 50% of the light is transmitid, with losses in intensity image, but one gains the final resolution.

Polarizing microscopy can be used with reflected and transmitted light. Reflected light is useful for study of opaque materials such as mineral oxides and sulfides, metals and silicon wafers and requires stress-free objectives that have not been corrected for viewing through a coverslip.

The reflected light microscope was created because it is not possible to observe metals with a transmitted light microscope, because the electrons of the conductive layer of metals interact strongly with photons, making these samples too little transparent.

Reflected light microscopy is often referred to as incident light, dpi-illumination, or metallurgical microscopy, and is the method of choice for fluorescence and for imaging specimens that remain opaque even when ground to a thickness of 30 micrometers. Much like the fluorescence microscope, in reflected bright field microscopy the sample is illuminated from above through the objective.

A very important technique in reflected light microscopy is the existence of a dark field, which allows through an oblique illumination (obtained by placing an obstacle in the center of the light beam) obtaining a bright contrast in regions which have a small inclination to the surface .

Notes

Reflected light microscopy is frequently the domain of industrial applications, especially in the rapidly growing semiconductor arena and this represents a most important segment of microscopical studies.

References

http://zeiss-campus.magnet.fsu.edu/articles/basics/reflected.html