out-of-focus information and thus produce an image of a very thin section of
a specimen. Third, because of the absence of out-of-focus information, much
higher-contrast images are obtained.
The confocal microscope, developed in 1957, uses point illumination and
a pinhole in front of the detector to eliminate out-of-focus information [2]. Only
the light within the plane of focus is detected, so the image quality is much better
than that of wide-field images. In contrast to wide-field microscopy, in most
confocal microscopes the illumination light is focused to the smallest possible
spot in the plane of focus, using a coherent light source such as a collimated
laser beam.
Confocal microscopes are categorized into two major types, depending
on the imaging ...