Optical spectroscopy of Sm3+ ions in phosphate and fluorophosphate glasses

• Published in: Optical materials Vol. 29; no. 11; pp. 1429 - 1439
• Main Authors: Venkatramu, V., Babu, P., Jayasankar, C.K., Tröster, Th, Sievers, W., Wortmann, G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-07-2007; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Decay time; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Glasses, quartz; Judd–Ofelt theory; Luminescence; Optical absorption; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Optics; Physics; Spectroscopic properties; 42.70.−a; 78.20.−e; 78.20.C; Decay time; 42.70.Ce; Luminescence; Spectroscopic properties; Optical materials; Judd–Ofelt theory; Optical absorption; Energy levels; Ground states; Doped materials; Excitation energy transfer; Phosphate glass; Excited states; Judd Ofelt effect; Lifetime; Samarium additions; Optical materials; Spectroscopic properties; Judd-Ofelt theory; Optical absorption; Luminescence; Decay time; Optical properties; Fluorophosphate glasses; Absorption spectra; 42.70.-a; 78.20.-e; 42.70.Ce; 78.20.C; Aluminium oxides
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2006.06.011

Spectral characterization of Sm3+-doped phosphate (PKBAS: P2O5+K2O+BaO+Al2O3+Sm2O3) and fluorophosphate (PKBFAS: P2O5+K2O+BaO+BaF2+Al2O3+Sm2O3) glasses through absorption, emission and decay curves are presented. The observed bands in absorption spectra, responsible for transitions from ground state to various excited states, are assigned and analyzed using free-ion Hamiltonian (HFI) model. Radiative properties are predicted using Judd–Ofelt theory. Experimental branching ratios and lifetimes of the 4G5/2 level are compared with theoretical values. The decay curves of Sm3+-doped phosphate and fluorophosphate glasses are perfectly single exponential for lower concentration (0.01mol%) and gradually change to non-exponential for higher concentrations. The analysis of non-exponential behavior of decay curves through Inokuti–Hirayama model indicates that the energy transfer between Sm3+ ions is of dipole–dipole type. Our systematic analysis on decay measurements reveals that energy transfer mechanism strongly depends on concentration as well as glass composition.