Confocal Laser Scanning Microscopy
In a confocal arrangement the objective is responsible both for the lighting and for collecting of light. By using a small aperture behind the collecting optics the transmitted light can be restricted to the focal plane. The detected light is either relfected or originates from fluorescence. Due to the diffractional limitation a laser beam can be focussed down best to the half of its wavelength. Scanning the sample the changes in intensity provide an image of the focal plane. For transparent materials also the inner areas are accessible and a 3D-microscopy can be realized.