Er3+/Yb3+ co-doped bismuthate glass and its large-mode-area double-cladding fiber for 1.53 μm laser

• Published in: Journal of alloys and compounds 2021-02, Vol.853, p.157305, Article 157305
• Main Authors: Song, Xiangyang, Jin, Danyang, Zhou, Dechun, Xu, Pengfei, Han, Kexuan
• Format: Article
• Language: English
• Subjects: 1.53 μm laser; Absorption spectra; Bismuth oxides; Bismuth trioxide; Bismuthate glass fiber; Cerium oxides; Cladding; Cut off wavelength; Diameters; Doped fibers; Double-cladding; Er3+/Yb3+ co-doped; Erbium; Fiber lasers; Gallium oxides; Germanium oxides; Large-mode-area; Laser outputs; Lasers; Numerical aperture; Optical fibers; Optical properties; Q factors; Radiative lifetime; Transition probabilities; Ytterbium
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.157305

Er3+/Yb3+ co-doped large-mode-area double-cladding fibers based on Bi2O3-GeO2-Ga2O3–Na2O–CeO2 glass material were fabricated using a rod-in-tube method. Due to the low core numerical aperture (NA = 0.057), the prepared fiber can operate in single-mode regime with a cut-off wavelength of ∼1.49 μm while its core diameter reaches 20 μm. Based on the measured absorption spectrum, the spectroscopic parameters of Er3+/Yb3+ co-doped core glass were calculated by Judd-Ofelt theory. Relatively large spectroscopic quality factor (χ = 3.139), spontaneous transition probability (266.58 s−1) and radiative lifetime (3.75 ms) indicate the core glass has good radiation characteristics. Moreover, under 980 nm excitation, the strongest 1.53 μm emission is achieved in core glass while the doping concentration ratio of Er3+/Yb3+ is 1.0 mol%: 2.5 mol%. And the maximum emission cross section is calculated to be 8.2 × 10−21 cm2 at 1532 nm by McCumber theory. Finally, a stable laser output at 1535.4 nm is achieved in a 50 cm long as-drawn Er3+/Yb3+ co-doped fiber, yielding a maximum laser output power of 93.64 mW and a slope efficiency of 11.75%. The excellent optical properties indicate the prepared Er3+/Yb3+ co-doped fibers have potential applications for 1.53 μm band high power fiber laser. •Large-mode-area double-cladding bismuthate glass fibers are fabricated.•Optical properties of the present bismuthate glasses are improved by CeO2.•Core and cladding glasses have excellent thermal properties and compatibilities.•Large τmea (4.12 ms) and σemi (8.2 × 10−21 cm2) have been realized in core glass.•A stable laser output is achieved in the present Er3+/Yb3+ co-doped optical fiber.