Over centuries, the classical optical microscope was the only tool that provided researchers images behind the limits defined by their eyes. During the last century light microscopy went through a tremendous development. But the basic idea of a lens or a set of lenses enlarging a reflective or transmitive image and making it visible to the eye of the viewer remained. Today, light microscopy shows a vast variety of different techniques. On the one hand, the classical light microscopy has been refined by additional contrast enhancing techniques. On the other hand, a complete new field of light microscopy has been established: the fluorescence microscopy. Here, the sample is excited to emit fluorescence light. Manipulating the excitation light and analyzing the emission light offers new ways of obtaining information about the often specifically prepared sample. This thesis deals mainly with a new way of excitation in fluorescence microscopy: the two-color two-photon (2c2p) excitation. For the first time femtosecond laser pulses are used to excite fluorescence by simultaneous absorption of two photons of different wavelengths. 超快門寬增強型CCD相機