Superbroadband near-infrared emission and energy transfer in Pr ³⁺-Er³⁺ codoped fluorotellurite glasses

We report the first demonstration of superbroadband emission extending from 1.30 to 1.68 μm in praseodymium(Pr³⁺)-erbium(Er³⁺) codoped fluorotellurite glasses under 488 nm excitation. This superbroad near-infrared emission is contributed by the Pr³⁺: ¹D ₂→¹G₄ and Er³⁺: ⁴I_13/2→⁴I_15/2 transitions which lead to emissions located at 1.48 and 1.53 μm, respectively. The quenching of the Pr³⁺ emission resulted from the cross relaxation [ ¹D₂, ³H₄]→[¹G ₄, ³F_3,4] was effectively compensated by the codoping of Er³⁺. The results suggest that, other than the heavy-metal and transition-metal elements of active bismuth (Bi), nickel (Ni), chromium (Cr), etc., Pr³⁺-Er³⁺ codoped system is a promising alternative for the broadband near-infrared emission covering the expanded low-loss window.