Broadband 2 μm emission characteristics and energy transfer mechanism of Ho3+ doped silicate-germanate glass sensitized by Tm3+ ions

2.0 μm Ultra Broadband Emission from Tm3+/Ho3+ Co-Doped Gallium Tellurite Glasses for Broadband Light Sources and Tunable Fiber Lasers

“…Energy levels above 1 G4 energy level of Tm 3+ and 5 G5 energy level of Ho 3+ are not clearly observed due to strong intrinsic bandgap absorption in the host glass. In addition, the peak positions of each absorption band for the Tm 3+ /Ho 3+ co-doped glass sample are very similar to those reported previously from other host glasses [7,19,20]. It is worth noting that there is a strong absorption band centered at 794 nm from Tm 3+ : 3 H6→ 3 H4 transition, which indicates that the commercial high-power 808 nm LD can act as an effective pump source for Tm 3+ singly doped and Tm 3+ /Ho 3+ co-doped samples.…”

“…Comparing the percentage of each phonon participation, one can observe that both energy transfer processes between Tm 3+ and Ho 3+ are almost resonant energy transfer with non-phonon creation or annihilation. It is worth mentioning that the forward energy transfer coefficient from Tm 3+ : 3 F4 to Ho 3+ : 5 I7 energy level (6.22×10 39 cm 6 /s) in the present glass is larger than that of germinate-tellurite glass (1.42×10 39 cm 6 /s) [33] and silicate-germanate glass (3.39×10 39 cm 6 /s) [20]. Therefore, Tm 3+ /Ho 3+ co-doped gallium tellurite glass with FWHM of 329 nm, larger emission cross section, and high CTm-Ho is a promising candidate for mid-infrared tunable fiber lasers.…”

“…It is worth mentioning that a flat ultra broadband 2.0 μm emission with FWHM of 329 nm is achieved in 1 mol.% Tm2O3 and 0.05 mol.% Ho2O3 co-doped gallium tellurite glasses, which is due to energy transfer process from Tm 3+ : 3 F4 to Ho 3+ : 5 I7 energy level and partial overlap of Tm 3+ : 3 F4→ 3 H6 and Ho 3+ : 5 I7→ 5 I8 transitions. The value is larger than that of Tm 3+ /Ho 3+ co-doped silicate-germanate glass (231.5 nm) [20] and silicate glass (189 nm) [24] and is slightly lower than that of Yb 3+ /Tm 3+ /Ho 3+ triply doped gallo-germanate glass (343 nm) [25]. Larger FWHM will provide a better opportunity to achieve broad amplified spontaneous emission (ASE) sources and tunable fiber lasers [4,7].…”

Investigation of intense mid-infrared emission in Ho3+/Yb3+/Er3+ triple-doped tellurite glass

“…In recent years, 2.0-μm solid-state lasers have been widely used in high-resolution molecular spectroscopy, biomedical systems, laser imaging, remote sensing, human eye safety lidar, and military equipment 1 – 4 Optical performance began to require more refined requirements. The research on improving the performance of solid-state lasers mainly focuses on the two aspects of laser gain materials and doped materials.…”

Luminescence features of Ho3+, Er3+ and Tm3+ ions in red lead added non‐conventional antimony oxide glass system

“…to the local Lorentz field, where n d is the refractive index and other symbols have their usual meanings as reported in Refs[43][44][45]. In Equation (3), ΔE ≈ 17,800 cm À1 (energy of the barycentre of Tm 3+ ion[51,52]) represents the additional quantities resulting from inter-configurational interactions (4f and 5d) andR 2 = R 6 = À 5 Â 10 À5 ; R 4 = 5 Â 10 À5 .Because the majority of transitions were anticipated to arise from energy levels below the barycentre of the Tm 3+ 4f12 configuration, the negative values of R 2 and R 6 were required.…”