We have developed a high intensity, dual-wavelength laser system to carry out vibrational excitations of molecules via mid-infrared radiation  or Raman Chirped Adiabatic rapid Passage (RCAP) [2,3]. We have previously reported amplifying two outputs from a dual-wavelength, mode-locked Ti:sapphire laser to a total energy of 1.5 mJ, in a single regenerative amplifier . Also we have reported the generation of 1.5 ILI pulses at 10 [an, from mixing the output of the two colour amplifier  . In this report, we describe a dual-wavelength, multi-pass amplifier, that increases the energy of the two pulses to a combined level of 15 mJ. The two pulses can be used directly in an RCAP experiment or be difference frequency mixed to generate high intensity mid-infrared radiation, for the chirped mid-infrared experiment. We have now increased the energy to 7.4[0, by using 4.7 mJ of energy from the multi-pass amplifier.