As told also by , "fluorescence or laser-excited luminescence has always been considered troublesome in Raman spectroscopy, since they easily mask the much weaker Raman signals and degrade the quality of the spectra. People have developed several strategies to eliminate the bad influence of fluorescence, … but it is still difficult to obtain pure Raman spectra without fluorescence interference in many cases" (see references in Yu et al.). For lanthanide materials, the situation becomes even worse because most of the lanthanide ions are luminescent and abundant luminescence bands are commonly seen in Raman spectra of them, which makes the interpretation of such spectra sometimes rather difficult. However, see this problem from a different view, fluorescence signals generated in Raman spectroscopy sometimes can also be helpful, since they may provide useful additional information of the material" . The previous research made by Yu and coworkers "indicates that Raman spectroscopy is ultrasensitive to lanthanide luminescence and thus can be utilized for detecting trace lanthanide impurities" . In the article by Yu and coworkers, we find the Raman spectra of rare earth sesquioxides RE2O3 (RE=Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y).