Broadband 2.9 μm mid-infrared fluorescence behavior of Dy3+/Tm3+ co-doped zirconium fluoride glasses

•With the introduction of Tm3+, Dy3+ can achieve broadband emission between 2600 and 3400 nm.•The mid-infrared fluorescence intensity enhanced with the increase of Tm3+ due to the energy transfer process between Dy3+ and Tm3+.•Larger absorption and emission cross-sections the glass owned, the gain coefficient was also greatly improved.•The fluorescence lifetime at 2.9 μm were prolonged with the addition of Tm3+. We report the 2600–3400 nm strong mid-infrared (MIR) fluorescence emission with the full width at half maximum (FWHM) of 355 nm in the zirconium fluoride glass incorporated with Dy3+, Tm3+ ions. In this paper, Dy3+, Tm3+ ions co-doped ZrF4-BaF2-LaF3-AlF3-YF3 zirconium fluoride glasses are synthesized by high temperature melting method. Structure information is obtained by raman spectroscopy, and the maximum phonon energy of the synthesized glass is 575 cm−1. Optical performance is mainly characterized by transmission spectrum, absorption spectrum and emission spectrum, theoretical analysis is described by Judd-Ofelt (J-O) theory, cross sections and gain coefficient. Under the 808 nm Laser Diode (LD), the 2.9 μm mid-infrared emission intensity is significantly enhanced with the introduction of Tm3+, and the fluorescence lifetime is prolonged 1.85 ms, the relevant energy transfer mechanism has been further analyzed. All results show that the new glass material may be a potential medium for mid-infrared broadband fiber amplifiers and lasers.