Selective excitation of CARS by adaptive pulse shaping based on genetic algorithm

Selective excitation of coherent anti-Stokes Raman scattering (CARS) from the benzene solution is experimentally demonstrated by shaping femtosecond laser pulses based on genetic algorithm. Second harmonic generation frequency-resolved optical gating (SHG-FROG) technique is adopted to characterize the original and optimal laser pulses, and the mechanisms for the coherently selective excitation of coherent anti-Stokes Raman scattering (CARS) is discussed. The results show that two-pulse coherent anti-Stokes Raman scattering (CARS) has good signal-to-background ratio and high sensitivity, and it has attractive potential applications in the complicated molecular system, such as biomolecules and materials.