Increasing your pulse rate let's you run faster.

One often reads that 2-photon microscopy does not bleach chromophores, compared to laser-scanning confocal microscopy, because it is a more gentle way of imaging. This is only partially true. Certainly 2PM causes less bleaching outside the focal volume, but since it generates the same excited state for imaging, it bleaches just as well in the image plane as LSCM. Betzig and Magee (Janelia Farms) have provided a clever solution to this problem: divide the imaging beam into smaller fragments, of lower energy and higher repetition rate. This trick allows them to scan a sample much faster (0.4 microseconds per pixel!), yet get a nicer image (i.e. better signal to noise), with much less photobleaching (see pic-I think they have mislabeled the lines in (i), the orange should be "with splitter"?). The gizmo they made is a "simple" modification of the Ultima 2PM that Jeff and I asked Prairie Technologies to make for us (one for each lab) in 2003.

Apparently, you can have your cake and eat it. Hey Jeff, I want one.

High-speed, low-photodamage nonlinear imaging using passive pulse splitters.
Nature Methods (2008) 5:197-202.