Core-clad terbium doped chalcogenide glass fiber with laser action at 5.38 μm

Abstract

The core-clad Tb3+-doped Ga-Ge-As-Se/Ge-As-S chalcogenide glass fiber is fabricated and tested in laser experiment. To prepare the high-purity terbium doped Ga-Ge-As-Se core glass, the special multi-stage purification technique is developed. The 1050 ppmw Tb3+-doped core Ga3.2Ge24.9As15.3Se56.6 glass is characterized by an extra-low content of limiting hydrogen impurity, high stability against crystallization and strong broadband photoluminescence in the middle infrared range. The doped chalcogenide fiber has a total diameter of 400 μm, a core diameter of 18 μm, and minimum optical losses of 3 ± 0.3 dB/m at a wavelength of 7.1 μm. Using a Tm3+ 1.98 μm fiber laser as a pump source, the threshold of 5.38 μm lasing with spike structure was reached in chalcogenide fiber for the first time.