An efficient 1.8μm emission in Tm3+ and Yb3+/Tm3+ doped fluoride modified germanate glasses for a diode-pump mid-infrared laser

• Published in: Journal of non-crystalline solids 2014-11, Vol.404, p.19-25
• Main Authors: Wang, W.C., Yuan, J., Liu, X.Y., Chen, D.D., Zhang, Q.Y., Jiang, Z.H.
• Format: Article
• Language: English
• Subjects: 1.8 μm emission; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Direct current; Emission; Exact sciences and technology; Excitation; Fluorides; Fundamental areas of phenomenology (including applications); Germanate glasses; Germanates; Glass; Glasses (including metallic glasses); Laser materials; Lasers; Materials science; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Optics; Physics; Searching; Semiconductor lasers; laser diodes; Specific materials; Upconversion
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2014.07.026

The competition between infrared down-conversion (DC) and visible up-conversion (UC) is systemically studied in Tm3+ and/or Yb3+/Tm3+ co-doped fluoride modified germanate glasses. Based on the absorption spectra, the Judd–Ofelt intensity parameters, absorption and emission cross-sections, figure of merit (FOM), and saturated gain coefficient are calculated and analyzed. An intense 1.8μm emission is obtained upon 808nm laser diode (LD) excitation in Tm3+ doped samples, while an efficient 1.8μm emission is observed by 980nm LD in Yb3+/Tm3+ co-doped samples, along with visible UC emissions. It is found that 3F4 state of Tm3+ can be easily populated and then further excited to higher excited states through Yb3+ upon 980nm LD. Our results suggest that these Tm3+ doped fluoride modified germanate glasses are of great significance for searching efficient mid-infrared laser materials. •The competition between infrared DC and visible UC is systemically studied.•Intense 1.8 µm emission is observed along with visible UC by 980 nm LD.•The fluoride modified germanate glasses may have application in diode-pump lasers.