Third-order nonlinear susceptibilities of several organic solvents are measured by third-harmonic generation at two laser wavelengths: 1.064 and 1.907 μm. The method used allows a determination of the modulus and phase by interference with the harmonic field generated in the liquid-cell windows. Air contribution to the resulting harmonic intensities is studied in detail. An experimental correction for this effect is proposed and verified for some solvents. Results are discussed within the bond-additivity model.

• Received 28 December 1984

DOI:https://doi.org/10.1103/PhysRevA.32.2352