From what I thought with Leica and the patent that is now up, you are free
to do what you want with your laser - but the Leica support is gone and the
Leica reps won't be in the room and won't help you if you do.  But that is
chaning, Zeiss of course sub-licensed two photon for the Olympus FV1000 and
should be doing so with Leica now.  The ridiculous thing in my view, for
people like me who build oscillators/opos and go back and forth from
femtosecond to picosecond all the time in my lab depending on what is best
for the student, is the idea that some day there may be a patent, "imaging
with sub 100fs" or "imaging with 2+ps" putting us all in a tight box, but I
have hope - when your lab gets to be like mine, all wires, all
home-modified, older equipment, jerry-rigged there are neither
service/support or patent issues to worry about.  If you're willing to be on
your own without help you can do what you wish, but I'm not a lawyer.

-Evangelos