Selective control of vibrational modes with sequential femtosecond-scale laser pulses

► Optimum FWHM laser pulse duration is 0.42 T for vibrational mode with period T. ► Much greater enhancement with optimized sequence of femtosecond-scale pulses. ► With enough optimized pulses, one can select various modes to be dominant. ► One can select modes useful in identifying or characterizing a chemical system.