Measurement of nonresonant third-order susceptibilities of various gases by the nonlinear interferometric technique

We applied nonlinear interferometry of coherent anti-Stokes Raman spectroscopy (CARS) to measure the nonresonant third-order susceptibilities of various gases. Using argon as an internal calibration standard, we determined the effective nonresonant susceptibilities of acetylene, carbon dioxide, methane, nitrogen, oxygen, propane, carbon monoxide, Freon, and hydrogen from the amplitudes of the interference fringes of the CARS signals generated in the two gas cells. The electronic susceptibility was calculated by subtracting the offresonant term of each molecule from the measured effective nonresonant susceptibility, and the results of this work are compared with the published data. The overall uncertainty is estimated to be less than 5%.