Lasers for fluorescence microscopy
CW lasers in the visible range are widely used in fluorescence microscopy applications. The fluorescence from specific fluorophores or biomarkers is detected in confocal configurations enabling fast and high spatial resolution imaging of cells, organisms, sub-cellular structures and cell dynamics in live cells.
The resolution of these imaging techniques is fundamentally limited to ~200 nm by the diffraction limit of the laser (the Abbe principle). Over the last decades a number of so called super-resolution imaging techniques have been developed that are capable of going beyond the diffraction limit through manipulation of the fluorescence signal. Examples of super-resolution imaging techniques include STED, STORM, PALM, SIM and RESOLFT. These new techniques have enabled dynamic studies of microbiological structures at molecular level in live cells and have revolutionized the field of light microscopy.