For Raman spectroscopy in general, as observed by Sadagov et al., 2020, "increasing employment of Raman spectroscopy for the qualitative and quantitative analyses of substances and materials requires to record accurate and device-independent Raman spectra. … To ensure the independence of the Raman spectra on the hardware, it is necessary to solve the following two problems", which are regarding the "calibration of the Raman spectrometer with respect to the wavenumber scale" and the calibration "with respect to the shape of the spectra, i.e., with respect to the relative intensities of the Raman peaks" . For what is regarding the special glass compositions, "the following requirements are imposed" by NIST: "(a) sufficiently strong fluorescence under the influence of laser radiation that excites Raman scattering, which is capable of ensuring Stokes shifts in the wavenumber range from 200 to 4000 cm -1 ; (b) photostability; and (c) low absorption at the wavelength of exciting radiation, which is required to prevent heating caused by laser radiation" . Sadagov and coworkers studied the "fluorescence calibration standards based on phosphate matrix glass activated with ions of rare-earth metals".