Single-mode large-mode-area Er–Yb fibers with core based on phosphorosilicate glass highly doped with fluorine

Abstract

Single-mode Er–Yb fibers with the core based on a phosphorosilicate glass matrix (up to 6.5 mol.% P2O5) highly doped with fluorine (up to 0.9 wt.%) were fabricated using an all-gas-phase modified chemical vapor deposition method. The core numerical aperture was in the range of 0.07–0.08 relative to the pure silica, which allowed us to increase the single-mode core diameter up to 20 μm. The slope efficiency in lasers based on the fabricated fibers reached 34% relative to the launched pump power.

Photosensitive Yb-Doped Germanophosphosilicate Artificial Rayleigh Fibers as a Base of Random Lasers

“…The RIP (Figure 2a) has a narrow dip in the core center, the nature of which is the partial loss of GeO2 and P2O5 components due to evaporation during the high-temperature collapse process of the tube preform [19]. At the same time, it should be noted that the width and depth of the central dip turned out to be noticeably smaller than the dip in preforms with a fluorophosphosilicate glass core manufactured by the same MCVD deposition method [12,13]. As we can see from Figure 2b, in the fiber core region (the range 20-40 µm along the X axis), the glass host dopant concentration is ~4 mol% of P2O5 and ~3 mol% of GeO2.…”

“…The Yb(thd) 3 chelate precursor was thermostat controlled at a temperature of 149 • C to secure an acceptable vapor pressure. The preform core glass was synthesized by means of an original technique where the separate deposition of glass host components and the active dopant was implemented; the deposition technique is described in detail in our previously published works [11][12][13]. At first stage of the technical process, a porous layer of the GeO 2 /P 2 O 5 /SiO 2 composition was deposited at a reduced temperature of~1400 • C. Then, Yb(thd) 3 vapors delivered by a carrier gas (argon) via delivery lines and a rotary seal (the units were heated up to~200 • C to prevent the vapors preliminary deposition) mixed with oxygen in the reference silica tube (Heraeus F300, outer diameter 15 mm, wall thickness 1.3 mm).…”

Theoretical and experimental investigation of Al3+ ion-suppressed phase-separation structures in rare-earth-doped high-phosphorus silica glasses

“…a Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics Highly phosphorus doped silica-based composite glasses are a key research area for high power gain fibers owing to their high solubility for RE ions and excellent anti-photon darkening capability. [26][27][28][29][30] In recent years, an increasing number of studies have been devoted to modulating the degree of constraint of the phosphate network on RE ions in order to achieve a balance between high luminescence efficiency and high doping homogeneity. [30][31][32][33] Likhachev et al prepared high-quality phosphorus-silica composite glass fibers by using the multilayer modified chemical vapor deposition (MCVD) technique.…”

Temperature Dependence of Absorption and Energy Transfer Efficiency of Er3+/Yb3+/P5+ Co-Doped Silica Fiber Core Glasses

“…Several studies have been conducted on the doping concentration and doping ratio of the Yb 3+ and Er 3+ ions in silica glass [24]. The results show that when the doping concentration of the Yb 3+ ions reaches 3-5 wt%, and the molar concentration ratio of Yb 3+ /Er 3+ ions is 8-15, the EYDF exhibits a better laser performance [10,[24][25][26]. However, the strong pump absorption of the Yb 3+ ions inevitably causes the temperature of the glass to rise.…”