Upconversion and excited-state absorption in the lower levels of Er:KPb2Cl5

• Published in: Optical materials 2008-02, Vol.30 (6), p.827-834
• Main Authors: Quimby, R.S., Condon, N.J., O’Connor, S.P., Biswal, S., Bowman, S.R.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Doped-insulator lasers and other solid state lasers; Energy transfer; Exact sciences and technology; Excited-state absorption; Fundamental areas of phenomenology (including applications); Laser materials; Lasers; Nonradiative decay; Optical materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optics; Other solid inorganic materials; Photoluminescence; Physics; Upconversion
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2007.03.002

Polarized excited-state absorption spectra for the 4I13/2→4I9/2 transition in Er:KPb2Cl5 were determined from the measured 4I9/2→4I13/2 emission spectra using the reciprocity relation of [D.E. McCumber, Phys. Rev. 136 (1964) A954]. From these spectra, the microparameters for energy transfer were found to be CDA=2.6×10−42cm6/s for (4I13/2,4I13/2)→(4I15/2,4I9/2) and CDD=6.9×10−39cm6/s for (4I13/2,4I15/2)→(4I15/2,4I13/2). The macroscopic upconversion coefficient was measured by comparing fluorescence intensities from the 4I13/2 and 4I9/2 levels, and found to be Cup=(2.6±0.4)×10−20cm3/s, in good agreement with the value calculated from the microparameters CDA and CDD. Energy transfer upconversion between two ions in the 4I13/2 level is orders of magnitude weaker than in other typical hosts, and this is predicted to lead to dramatically reduced heat loading in a resonantly pumped 1.5μm Er laser.