Cr:Forsterite-laser-based fiber-optic nonlinear endoscope with higher efficiencies

We demonstrate a beam-scanning nonlinear light endoscope based on a flexible fiber bundle. Excited with a femtosecond Cr:Forsterite laser, the degradation in multiphoton multiharmonic excitation efficiency due to the pulse-broadening effect is significantly reduced without utilizing any external devices. The system resolution has been characterized to be 5.4 μm in the two-photon fluorescence endoscope, limited by the sampling theory. Finally, several image examples have been given. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc.