Optimized NIR and MIR emission properties of Tm3+/Ho3+ ions in lead sulfo phosphate glasses

[Display omitted] •Tm3+ and Tm3+/Ho3+ co-doped lead phosphate glasses were synthesized by standard melt quench technique.•The UC, NIR and MIR emission properties are studied with 797 nm LD pumping.•GTmHo-0.9 glass shows highest emission cross-section and gain coefficient.•• CIE coordinates from PL spectra provided scope for W-LED applications. The Tm3+/Ho3+ co-doped sodium-sulfo lead phosphate glasses (GTmHo-x) were synthesized by melt-quenching technique. The basic characterizations like XRD, FTIR are performed to analyse the structural behaviour in the glasses. The optical absorption studies were carried out. The NIR and MIR photoluminescence (PL) spectra were recorded at 797 nm excitation for GTmHo-x (x = 0.3, 0.6, 0.9, 1.2 and 1.2 mol%) glasses. The properties of emission bands at 1.4 μm, 1.8 μm and 2.0 μm corresponding to Tm3+:3H4, Tm3+:3F4, and Ho3+:5I7 transitions respectively, were studied. The NIR, Tm3+:3H4 (1.4 μm) emissions with broad full width half-maxima for single Tm3+ (121 nm) and Tm3+/Ho3+ co-doped (126 nm) were noticed in sodium-sulfo lead phosphate glasses. The highest PL emission intensity was obtained for GTmHo-0.9 glass. Moreover, the intensities of the Tm3+:1.8 μm and Ho3+:2.0 μm exhibited reverse trend in GTmHo-x glasses. To analyse the fluorescence behaviour, the energy transfer mechanism from various levels of Tm3+ → Ho3+ ions have been figured out and discussed. Further, the stimulated emission cross-section of Tm3+:1.8 μm and Ho3+:2.0 μm in single Tm3+ and Tm3+/Ho3+ co-doped glasses were calculated. The highest emission intensity, gain coefficient and emission cross-section of 0.9 mol% Ho3+ ion concentration suggests that GTmHo-0.9 glass is the favourable glass to perform highest MIR 2.0 μm emission. In short, the prepared GTmHo-x glasses might be a promising material for S-band (1.4 μm) amplifier in telecommunications and MIR (2.0 μm) solid-state lasers.