Laser, Optics, Optoelectronics and Nanophotonics

Optical properties of Ce³⁺/Tb³⁺-codoped borosilicate glass*

T. Tsuboi

Faculty of Engineering, Kyoto Sangyo University, Kamigamo, Kita-ku, Kyoto 603-8555, Japan

Abstract

Absorption spectra, luminescence spectra and luminescence decay time are investigated for a borosilicate glass containing low 0.1 wt% Ce³⁺ and high 15 wt% Tb³⁺ concentrations, together with the time-resolved luminescence. A broad absorption band due to parity allowed f → d transition is observed for Ce³⁺. Sharp absorption bands are observed in 3100–1600 nm region which are due to the ⁷F₆ → ⁷F _J (J = 0, 1, 2, 3, 4) transition of Tb³⁺, while much weak absorption bands due to the spin-forbidden ⁷F₆ → ⁵D _J (J = 2, 3, 4), ⁵G _J (J = 3, 5, 6), ⁵L _J (J = 7, 8, 9, 10), ⁵H _J (J = 4, 5, 6), ⁵I _J (J = 7, 8) and ⁵F _J (J = 2, 4) transitions are observed in visible-UV region. By excitation with 266 nm laser line, two broad UV emission bands due to Ce³⁺ are observed at 360 and 390 nm besides the intense green emission bands due to the ⁵D₄ → ⁷F _J (J = 6, 5, 4, 3) transition of Tb³⁺ and weak blue emission bands due to the ⁵D₃ → ⁷F _J (J = 6, 5, 4, 3) transition. The decay time of the UV, blue and green emission is estimated to be 17 ns, 3.8 µs and 2.17 ms, respectively. The rise time of the green emission is about 4 µs after the Ce³⁺ emission and the Tb³⁺ blue emission. No rise time is observed for the latter emission.

(Received June 10 2003)

(Revised September 22 2003)

(Accepted December 11 2003)

(Online publication March 10 2004)

PACS:

• 34.30.+h – Intramolecular energy transfer; intramolecular dynamics; dynamics of van der Waals molecules;
• 78.40.-q – Absorption and reflection spectra: visible and ultraviolet;
• 78.60.-b – Other luminescence and radiative recombination

tsuboi@cc.kyoto-su.ac.jp

Footnotes

^*  This paper has been presented at “Advanced Research Workshop: Physics of Laser Crystals", 26 August–2 September 2002, Kharkiv-Stary Saltov, Ukraine.