Abstract

Recent years, rare earth ions doped oxyfluoride glass-ceramics have been paid much attention due to their combined advantages of oxide glasses and fluoride glasses: high chemical and mechanical stability and low phonon energy ^1,2. In this paper, a transparent Tb³⁺ and Yb³⁺ codoped oxyfluoride glass-ceramic containing CaF₂ nanocrystals was prepared through thermal treatment to develop UV laser media. The result of X-ray powder diffraction measurement show there exist CaF₂ nanocrystals with the size of about 8 nm, as shown in Fig. 1. The visible emission spectra of the as-made glass and the glass-ceramic with the excitation of a 374 mW 974 nm diode laser are shown in Fig. 2. The spectra consist of seven emission bands centered at 381 nm, 415 nm, 437 nm, 490 nm, 546 nm, 588 nm, and 622 nm, which are attributed to the transitions of ⁵G₆,⁵D₃→⁷F₆;⁵G₆,⁵D₃→⁷F₅;⁵G₆,⁵D₃→⁵F₄;⁵D₄→⁷F₆;⁵D₄→⁷F₅;⁵D₄→F₄; and ⁵D₄→⁷F₃ of Tb³⁺ ion; respectively. All the intensities of these emissions increased except for that of the emission at 546 nm after thermal-treatment and the emission intensity ratios with the emission at 546 nm (specified as I/I₅₄₆ thereafter) increased in a different gratitude. The intensity of the UV emission at 381 nm could be enhanced using a glass ceramic host.

© 2007 IEEE