Emission properties of Pr³⁺-doped aluminosilicate glasses at visible wavelengths

In this work, we explore emission properties of Pr³⁺ ion doped aluminosilicate glasses at visible wavelengths where alkaline earth oxide modifiers (Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺) are introduced for enhancement of the Stark splitting of Pr³⁺ in the silicate matrix. The Pr³⁺ ion doped aluminosilicate glasses present strong absorption at visible wavelengths between 440 and 500 nm which gives rise to intense emission in the visible spectrum from 570 to 660 nm. The visible luminescence spectra under excitation at different pump wavelengths and the lifetime of spontaneous emission are investigated as functions of Pr³⁺ doping concentration. We report a longest lifetime of 115 μs measured at ³P₀ level in Pr³⁺ implying Pr³⁺ doped aluminosilicate glass may be a promising candidate for efficient visible fiber laser operated at 610 and 640 nm wavelength. The concentration-induced quenching and various energy transfer processes are also investigated.