Optical spectroscopy and energy transfer in Tm3+-doped metaphosphate laser glasses

• Published in: Journal of physics. Condensed matter 2005-08, Vol.17 (32), p.4859-4876
• Main Authors: Babu, P, Seo, Hyo Jin, Jang, Kyoung Hyuk, Balakrishnaiah, R, Jayasankar, C K, Joshi, A S
• 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: 10.1088/0953-8984/17/32/001

Thulium-doped metaphosphate glasses with four concentrations (0.01, 0.1, 1.0 and 2.0 mol%) of Tm3+ have been prepared and investigated by Raman, absorption and photoluminescence spectral studies. The phonon sideband spectrum has been measured for 1.0 mol% Eu3+-doped metaphosphate glass of the same composition and compared with the Raman spectrum. From vibronic spectra, various bands associated with different structural groups have been identified and assigned. Absorption band positions have been used to simulate the complete energy level diagram for the Tm3+ ion using the model Hamiltonian. JuddOfelt parameters have been determined from the absorption bands. Using these parameters, transition probabilities, excited state lifetimes and transition branching ratios have been evaluated. The emission and decay curves of the ID2 level have been measured for all four glass samples both at RT and 15 K. Lifetimes show a strong quenching for Tm3+ concentrations higher than 0.1 mol%. Fluorescence decay curves of the ID2 level have been well fitted to the InokutiHirayama model for S = 6, suggesting that the mechanism for energy transfer between Tm3+ ions is of dipoledipole type.