Superbroadband NIR Photoluminescence in ${\rm Nd}^{3+}/{\rm Tm}^{3+}/{\rm Er}^{3+}$ Codoped Fluorotellurite Glasses

We report the superbroadband photoluminescence extending from 1.3 to 1.7 μm in Neodymium(Nd³⁺)/Thulium(Tm³⁺)/Erbium(Er³⁺) codoped fluorotellurite glasses under 793 nm excitation. This superbroadband luminescence is contributed by the Nd³⁺:⁴F_3/2→⁴I_13/2, Tm³⁺:³H₄→³F₄, and Er³⁺:⁴I_13/2→⁴I_15/2 transitions that lead to broadband emissions located at 1.34, 1.47, and 1.53 μm, respectively. Broadband emission spectrum is also obtained in the ion-exchanged planar waveguide fabricated on Nd³⁺/Tm³⁺/Er³⁺ codoped fluorotellurite glass. The results indicate that other than active Bismuth (Bi), Chromium (Cr), Nickel (Ni), and other chemical elements, Nd³⁺/Tm³⁺/Er³⁺ codoping is a promising alternative for the broadband luminescence sources covering the expanded low-loss window.