The relative Raman cross sections of vitreous SiO2, GeO2, B2O3, and P2O5

We report the relative HH Raman spectra obtained from high-purity bulk samples of the primary glass formers SiO2, GeO2, B2O3, and P2O5. With 514.5-nm excitation, the peak Raman cross sections of these glasses have relative strengths of 1, 9.2, 4.7, and 5.7, respectively. The superior scattering strength of the latter three glasses suggests that they be used for increasing the gain and tuning range of fiber Raman lasers. The Raman spectra of mixed glasses containing GeO2, P2O5, and Na2O (or K2O) indicate that lasers made of these or similar materials may be continuously tunable over a range of 1300 cm−1.