Innovations in ultrafast lasers for nonlinear microscopy

Ultrafast laser sources are a key enabling technology for nonlinear excitation in multiphoton microscopy. Rapid developments in recent years resulted in a widening selection of laser formats and the expansion of the parameter space that can address existing and emerging applications. As an example, compact, fixed wavelength, ultrafast systems became as well established as the classical tunable femtosecond lasers. More sophisticated laser functionality, such as dispersion precompensation or integrated fast power modulation, now even comes as standard with most laser choices. Here we will review the latest novelties in ultrafast lasers and their impacts in the field of nonlinear imaging.