Simultaneous acquisition of pure rotational and vibrational nitrogen spectra using three-laser coherent anti-Stokes Raman spectroscopy

Three-laser coherent anti-Stokes Raman scattering (CARS) was used to acquire simultaneously pure rotational and vibrational spectra from the nitrogen molecule. This technique has the potential for accurate temperature measurements over a wider temperature range than either vibrational or pure rotational CARS alone. Third-order susceptibilities for three-laser CARS are derived, and polarization effects are discussed.