Laser Characteristics of Er3+/Yb3+:K-BaF2-Al-Phosphate Glasses

Er3+ and Er3+/Yb3+-doped phosphate-based glasses have been synthesized by melt quenching technique and are characterized by absorption spectra, infrared emission, decay curves, Fourier transform infrared spectrum and up-conversion studies. From the absorption spectra, intensity parameters and radiative properties have been derived utilizing the Judd-Ofelt theory. Er3+-doped glass is found to have larger radiative lifetime for the laser originating from I-4(13/2) level at 1537 nm. Infrared and visible characteristic emissions have been measured by exciting at 790 nm through down- and up-conversion, respectively. The up-conversion spectra consist of intense green emission at around 525 and 545 nm ascribed to the H-2(11/2) -> I-4(15/2) and S-4(3/2) -> I-4(15/2) transitions, respectively, and a weak red emission at around 656 nm due to the F-4(9/2) -> I-4(15/2) transition of Er3+ ions. Various spectroscopic and laser characteristics of these glasses have been calculated and compared with those of similar reported ones.