Coherent anti-Stokes Raman scattering under frequency comb excitation.

We study the efficiency of coherent anti-Stokes Raman scattering (CARS) under frequency comb excitation. We calculate the power density of the anti-Stokes signal for two major cases: (1) molecular excitation by frequency comb and cw probe and, (2) both excitation and probing by frequency combs. In the first case, average CARS power varies as an inverse third degree of frequency combs free spectral range (FSR-3); in the second case, it varies as FSR-5. These results were applied to the CARS on blood glucose under frequency comb excitation. It was found that the resulting glucose CARS signal could approach nanowatt (nW) level at FSR=10  GHz.