  Label-free nonlinear optical microscopy has become a powerful tool for
biomedical research. However, the possible photodamage risk hinder further
clinical applications. To reduce these adverse effects, we constructed a new
platform of simultaneous label-free autofluorescence multiharmonic (SLAM)
microscopy, featuring 5-channel multimodal imaging, inline photodamage
monitoring, and pulse repetition-rate tuning. By the use of a birefringent
photonic crystal fiber for spectral broadening (rather than supercontinuum
generation) and a prism compressor for pulse pre-chirping, this system allows
users to independently adjust pulse width, repetition rate, and energy, which
is useful for optimizing imaging condition towards no/minimal photodamage.
Also, it demonstrates label-free multichannel imaging at one excitation pulse
per image pixel and thus paves the way for improving the imaging speed by a
faster optical scanner.
