1.47-μm emission of Tm³⁺ ions in potassium lanthanum gallate glasses

Thulium-doped potassium lanthanum gallate glasses (K₂O-La₂O₃-Ga₂O₃ or KLG) which are suitable to use in amplifiers has been fabricated and characterized. The density, the refractive indexes, the absorption and luminescence spectra were measured and analyzed. By using the Judd–Ofelt theory, the experimental oscillator strengths, the Judd–Ofelt intensity parameters Ω_t were determined, and some important radiative properties were calculated. Using a least-squares fitting approach, the Judd–Ofelt intensity parameters Ω_t were found to be Ω₂=7.26×10^-20cm², Ω₄=1.69×10^-20cm², and Ω₆=0.66×10^-20cm². The bandwidth of the ³H₄→³F₄ transition around 1.47μm in Tm³⁺-doped KLG glasses is ~92nm which is smaller than Tm³⁺-doped KBG glasses at ~120nm.