The rare earth elements (R) form a series of highly stable glasses with compositions in the vicinity of (R203)0.25(P205)0.75 which include the most magnetic oxide glasses yet found an in consequence show a wide variety of fundamentally interesting and useful magneto-optical properties. To provide detailed comparative information of the optical properties of the series of rare earth doped metaphosphate glasses needed for device applications, the absorption and fluorescence spectra of glasses modified with Pr, Nd, Sm, Eu, Tb, Dy, Ho and Er have been determined over the wavelength range 400-1750nm. By comparing the measured transition wavelengths with those found in the optical spectra known for other hosts of rare earth ions, it is possible to account for virtually all the observed optical features.
