Spectroscopy and frequency upconversion in Nd3+-doped TeO2–TiO2–Nb2O5 glass

• Published in: Journal of physics. Condensed matter 2007-02, Vol.19 (8), p.086223-086223 (12)
• Main Authors: Balda, R, Fernández, J, Arriandiaga, M A, Fernández-Navarro, J M
• Format: Article
• Language: English
• Subjects: Amorphous materials, glasses and other disordered solids; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/19/8/086223

In this work, we report the optical properties of Nd3+ ions in tellurite glasses (TeO2-TiO2-Nb2O5) for two different Nd3+ concentrations. Judd-Ofelt intensity parameters were derived from the absorption spectrum and used to calculate the radiative lifetime and stimulated emission cross section of the transition. The non-exponential character of the decays from the 4F3/2 level and the reduction of the lifetime even at low temperature as Nd3+ concentration increases reveal the presence of nonradiative processes. The time evolution of the decays from the 4F3/2 level is consistent with a dipole-dipole direct energy transfer mechanism. Upconversion processes that produce green, orange, and red emissions after infrared excitation in the 4F3/2 and 4F5/2 levels have been investigated by using steady-state and time-resolved laser spectroscopy. The characteristics of the excitation spectra together with the temporal behaviour of the decays from the upconverted luminescence suggest that energy transfer upconversion processes are the dominant mechanisms in such emissions.