A nonlinear fluorescence imaging system and method for generating fluorescence imaging includes a pulsed laser source for generating laser pulses at a first wavelength and an optical pulse stretcher including one or more optical pulse stretcher fibers having a first dispersion parameter at the first wavelength. The system also includes a probe for interfacing with a sample to deliver the laser pulses and extract fluorescence signals excited in the sample. One or more optical delivery fibers are included for delivering the laser pulses and collecting nonlinear fluorescence signals. The optical delivery fiber has a second dispersion parameter at the first wavelength which is opposite a polarity of the first dispersion parameter. A detector detects images based on the collected fluorescence signals.