Preparation of high purity Sm3+-doped Ga-Ge-As-Se glass and low-loss fiber

Abstract

The high-purity 700 ppmw Sm3+-doped Ga2.2Ge26.5As14.6Se56.7 glass is prepared and investigated. The glass has an extra-low content of impurities, a wide transmission range (0.9–16 μm), a high glass transition temperature (330 °C), and high stability against crystallization. The low content of limiting impurities is the result of the multistage procedure for the purification of individual components, the basic glass-forming melt, as well as the chemical transport reactions technique. The Sm3+-doped Ga-Ge-As-Se glass shows photoluminescence in the spectral regions 1.2–1.3 μm, 1.4–1.6 μm, 1.75–2 μm, 2.2–3 μm, and 3.5–4.2 μm. In a complex system of samarium levels, the longest-lived energy transition is established to be the one at 3.7 μm with a lifetime of 60 μs From the high-purity Sm3+-doped Ga-Ge-As-Se glass, the single-index fiber with minimum optical loss of 0.5 dB/m at 5.7 μm and without impurity bands in spectrum is fabricated. It is the best result concerning the glass purity and optical loss among Sm3+-doped chalcogenide glass fibers.