A mid-infrared (MIR) supercontinuum (SC) has been demonstrated in a low-loss telluride glass fiber. The doublecladding fiber, fabricated using a novel extrusion method, exhibits excellent transmission at 8-14 μm: < 10 dB/m in the range of 8-13.5 μm and 6 dB/m at 11 μm. Launched intense ultrashort pulsed with a central wavelength of 7 μm, the step-index fiber generates a MIR SC spanning from ß2.0 μm to 16 μm, for a 40-dB spectral flatness. This is a fresh experimental demonstration to reveal that telluride glass fiber can emit across the all MIR molecular fingerprint region, which is of key importance for applications such as diagnostics, gas sensing, and greenhouse CO 2 detection.

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The spectroscopic properties and thermal stability of Er2O3 doped Bi2O3–B2O3–Na2O glasses are investigated experimentally. A close correlation is observed between the B2O3 content and the spectroscopic properties such as Judd–Ofelt intensity parameters Ωt (t=2,4,6), emission spectra, and lifetime of I13/24 level of Er3+. The value of Ω6 increases with an increase of B2O3 content, which is attributed to the decrease of the covalency of Er–O bond in terms of the glass microstructure and electronegativity theory. The emission spectra of I13/24→4I15/2 transition broadens as a consequence of the enhancement of the inhomogeneous distribution of Er3+ sites when increasing B2O3 content. The lifetime of I13/24 level of Er3+ in bismuth-based glass, compared with those in other glasses, is relative low due to the high-phonon energy of the B–O bond, the large refractive index of the host, and the existence of OH− in the glass. In addition, the glass stability is improved in which the substitution of B2O3 for Bi2O3 strengthens the network structure. The suitability of bismuth-based glass as a host for Er3+ doped for a broadband amplifier and its advantages over other glass hosts are also discussed.

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Nickel ion doped transparent bulk glass-ceramics containing K 2 SiF 6 , ZnF 2 , and KZnF 3 nanocrystals were elaborated to show the prospect that this novel group of oxyfluoride glass-ceramics is promising for transition metal ion based photonics. These new oxyfluoride glass-ceramics exhibit a new broadband luminescence of Ni 2+ ions in the intriguing near-IR spectral region ranging from 1200 to 2400 nm. Ni 2+ ions are incorporated into the precipitated K 2 SiF 6 , ZnF 2 , and KZnF 3 crystals, which provide octahedral sites for Ni 2+ and make it optically active. Taking into account the microstructure of phase separation observed by replica TEM, a detailed mechanism of phaseseparation-assisted nanocrystallization was described for these oxyfluoride glasses. These results allow one to establish a full physical model of the nanocrystallization mechanism. For the precipitation of fluoride crystallites, not only can the nanometric size be explained but also the formation of different crystal phases can be controlled by the initial amorphous phase separation of droplet or interpenetrating structure with a sufficiently elaborated glass design.

We report the fabrication of a novel high nonlinear fiber made of Ge-Sb-Se chalcogenide glasses with high numerical aperture (∼1.0), where the core and the cladding glasses consist of Ge₁₅Sb₂₅Se₆₀ and Ge₁₅Sb₂₀Se₆₅ (mol. %), respectively. The nonlinear refractive index (n₂) of the core glass is 19×10^-18 m²/W at 1.55 μm, and its laser-induced damage threshold under irradiation of 3.0 μm fs laser is approximately 3674  GW/cm². By pumping a 20-cm-long fiber with a core diameter of 23 μm using 150 fs pulses at 6.0 μm, supercontinuum spanning from ∼1.8 to ∼14  μm was generated.