Triple-resonance coherent anti-stokes Raman scattering microspectroscopy.

Fluorescence-free microscopy: A new nonlinear optical microspectroscopy technique, femtosecond (fs) triple-resonance coherent anti-Stokes Raman scattering, in which the amplitude and phase of input fs laser pulses are optimally shaped to be in triple resonance with the molecular electronic and vibrational transitions, generates a coherent nonlinear signal beam at a new color with a highest possible efficiency (see figure).