We report the first observation of third-order hyper-Rayleigh scattering superimposed on three-photon- induced fluorescence in a chloroform solution of the azobenzene dye Disperse Red 1. Cubic dependence of the intensity of the scattered third-harmonic light on the intensity of the fundamental light was observed. The intensity of the scattered third-harmonic light was linearly proportional to the number density of the dye. The estimated value of third-order polarizability ₃₃₃₃ of the dye under resonance conditions was 8.710^-33 esu.

DOI: 10.1143/JJAP.39.L1060