Tm3+-doped barium antimony germanate glass fibers for achieving 1.8-2 μm lasers

Near- and mid-infrared fiber lasers at the similar to 2 mu m wavelength range are essential for applications such as medical diagnostics, environmental monitoring, and military confrontation. However, developing materials that provide both anti-crystallization stability and high gain in this range remains challenging. This study presents the development of high-gain Tm3+-doped barium antimony germanate (BaO-Sb2O3-GeO2, abbreviated as BSG) glass fiber, designed to achieve laser emission at 1.8-2 mu m. Based on the glass-forming region, the composition of BSG bulk glass is optimized, and it exhibits a high Tm3+ doping concentration (N = 3.3 x 1020 ions/cm3), excellent anti-crystallization stability (AT = 250 degrees C), and a large emission cross-section (sigma e = 8.4 x 10-21 cm2). Tm3+-doped BSG optical fibers are fabricated using a melting-quenching method with a large full width at half-maximum of up to 200 nm in their amplified spontaneous emission spectra. Such Tm3+-doped BSG fibers produced gain coefficients of 6.48 dB/cm at 1950 nm and 6.03 dB/cm at 1867 nm when pumped at 1570 nm, respectively. Furthermore, laser outputs of 1862 nm and 1964 nm are achieved using a 2 cm long Tm3+-doped BSG glass fiber, highlighting the potential of BSG glass fibers in near- and mid-infrared laser applications. (c) 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.