Intense O+ E + S-band emission from Pr3+-doped ZnF2-based glasses

Pr3+-doped ZnF2-based glasses were prepared by using a melt-quenching method in dry N2 atmosphere. Under the excitation of a 588 nm light emitting diode (LED), ultrabroadband emissions ranging from 1245 to 1640 nm were obtained from the Pr3+-doped ZnF2-based glasses, which originate from the transitions 1D2→1G4 (producing E + S-band emission) and 1G4→3H5 (producing O-band emission) of Pr3+. The shape of the emission spectra could be tailored by varying the concentration of Pr3+. Emission spectra with the maximum full width at half maximum (FWHM) of 215 nm (1289 nm-1504 nm, covering the O+ E + S-band) was obtained in the ZnF2-based glass at a doping concentration of 5000 ppm. The effects of the phonon energy of the matrix on O+ E + S-band emission were also investigated. Our results showed that Pr3+-doped ZnF2-based glasses with low phonon energy might be used for constructing O+ E + S-band lasers and optical amplifiers.