Abstract : Multiphoton microscopy (MPM) has been greatly developed for about 25 years as an elegant alternative to classical fluorescence methods such as confocal microscopy for imaging biological specimens at the micron scale. In this topical review, the main interests and technical requirements of MPM are resumed with a focus on the crucial role of excitation source for optimization of multiphoton processes. Then, an overview of the different sources successfully demonstrated in the literature for MPM is presented and their physical parameters are inventoried. A classification of these sources in function with their ability to optimize multiphoton processes is proposed, following a protocol found in literature. Starting from these considerations, a suggestion of a possible identikit of the ideal laser source for MPM concludes this topical review.
