Vibrational imaging with high sensitivity via epidetected coherent anti-Stokes Raman scattering microscopy - art. no. 023901

We demonstrate theoretically and experimentally a novel epidetection scheme for coherent anti-Stokes Raman scattering (CARS) microscopy that significa ntly improves the detection sensitivity. Calculations show that epidetected CARS (E-CARS) signals are present for scatterers smaller than the waveleng th of light, whereas the large background signals from the:surrounding bulk solvent are suppressed by destructive interference. E-CARS microscopy is c apable of revealing small intracellular features that are otherwise buried by the strong water CARS signal.