Europhys. Lett.
Volume 71, Number 3, August 2005
Page(s) 394 - 399
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 06 July 2005
Europhys. Lett., 71 (3), pp. 394-399 (2005)
DOI: 10.1209/epl/i2005-10092-4

Self-absorption and radiation trapping in $\chem{Er^{3+}}$-doped $\chem{TeO_2}$-based glasses

M. Mattarelli1, M. Montagna1, L. Zampedri1, A. Chiasera2, M. Ferrari2, G. C. Righini3, L. M. Fortes4, M. C. Gonçalves4, L. F. Santos4 and R. M. Almeida4

1  Dipartimento di Fisica, Università di Trento, GCSMFO Via Sommarive 14, I-38050 Povo, Trento, Italy
2  IFN-CNR, Istituto di Fotonica e Nanotecnologie, GCSMFO Via Sommarive 14, I-38050 Povo, Trento, Italy
3  IFAC-CNR, Istituto di Fisica Applicata "Nello Carrara" Via Panciatichi 64, I-50127 Firenze, Italy
4  Departamento de Engenharia de Materiais, Instituto Superior Técnico A. Rovisco Pais, 1049-001 Lisboa, Portugal

received 13 January 2005; accepted in final form 1 June 2005
published online 6 July 2005

The 1.5 $\un{\mu m}$ fluorescence shape and lifetime of $\chem{Er^{3+}}$-activated tellurite glasses have been investigated. The measures on bulk system have been compared with those obtained on powders, showing that the self-absorption effect broadens the emission spectrum and lengthens the lifetime. It has been demonstrated that the bandwidth and lifetime measurements depend on the absorption coefficient $\alpha(\lambda)$ and on the distance d between the focused exciting laser beam and the exit face of a bulk glass sample. The actual emission spectrum has been reconstructed from the $\alpha(\lambda)\!\cdot\!d$ knowledge. Lifetime lengthening cannot be determined from $\alpha(\lambda)\!\cdot\!d$ and, to obtain actual lifetime for highly $\chem{Er^{3+}}$-doped glasses, measurements on powders are required.

42.70.Hj - Laser materials.
78.55.-m - Photoluminescence, properties and materials.
78.40.-q - Absorption and reflection spectra: visible and ultraviolet.

© EDP Sciences 2005