Experimental evidence on the source of negative peaks in coherent anti‐Stokes Raman spectra

摘要: Under certain conditions, when the laser pump frequency approaches an electronic transition frequency, negative peaks have been observed in coherent anti‐Stokes Raman spectra. Two conflicting explanations of this phenomenon offered. We noted that these two lead to a different dependence intensity on power beam. experimentally determined case 5×10−3M solution N, N‐diethyl‐p‐nitrosoaniline benzene and found varies with square This result is consistent explanation arise from cross term between background susceptibility imaginary part not inverse effect.