Excited state dynamics in Ho:KPb2Cl5

• Published in: Optical materials Vol. 34; no. 9; pp. 1603 - 1609
• Main Authors: Quimby, R.S., Condon, N.J., O’Connor, S.P., Bowman, S.R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2012
• Subjects: Chloride crystal; Cross sections; Emission; Emission spectra; Energy gap; Fluorescence; Infrared; Lifetime; Mathematical analysis; Multiphonon; Nonradiative; Oscillator strengths; Spectral emissivity; Fluorescence; Nonradiative; Lifetime; Multiphonon; Chloride crystal
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2012.04.004

► Optical absorption and emission spectra were measured for Ho3+ doped KPb2Cl5. ► Judd–Ofelt parameters were determined using two different methods. ► Calculated and measured fluorescence lifetimes agree within ≈15%. ► Small multiphonon relaxation rates are confirmed in this low phonon host. ► Emission cross section spectra are presented for five visible and infrared transitions. Optical absorption spectra, emission spectra, and fluorescence lifetimes were measured for a number of visible and infrared transitions in Ho3+ doped KPb2Cl5. Judd–Ofelt parameters were obtained by using the conventional approach, as well as by a modified approach that minimizes the fractional difference, rather than the absolute difference, between calculated and measured oscillator strengths. Both procedures gave good overall agreement between measured and calculated lifetimes, with an average difference of ≈15%. This confirms the expectation from the multiphonon energy gap law that most observed transitions in Ho3+:KPb2Cl5 are highly radiative. Emission cross section spectra for the transitions 5F3→5I8, 5G5→5I7, 5F3→5I7, 5F4/5S2→5I7, and 5I7 →5I8 were obtained from measured emission spectra, with the peak cross section values scaled by the Judd–Ofelt calculated oscillator strengths.