Progress in rare-earth-doped mid-infrared fiber lasers

• Published in: Optics express Vol. 18; no. 25; pp. 26704 - 26719
• Main Authors: Seddon, Angela B, Tang, Zhuoqi, Furniss, David, Sujecki, Slawomir, Benson, Trevor M
• Format: Journal Article
• Language: English
• Published: United States 06.12.2010
• Subjects: Chalcogens - chemistry; Computer Simulation; Computer-Aided Design; Crystallization; Equipment Design; Equipment Failure Analysis; Fiber Optic Technology - instrumentation; Glass - chemistry; Infrared Rays; Lasers; Metals, Rare Earth - chemistry; Miniaturization; Models, Theoretical; Refractometry - instrumentation
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/oe.18.026704

The progress, and current challenges, in fabricating rare-earth-doped chalcogenide-glass fibers for developing mid-infrared (IR) fiber lasers are reviewed. For the first time a coherent explanation is forwarded for the failure to date to develop a gallium-lanthanum-sulfide glass mid-IR fiber laser. For the more covalent chalcogenide glasses, the importance of optimizing the glass host and glass processing routes in order to minimize non-radiative decay and to avoid rare earth ion clustering and glass devitrification is discussed. For the first time a new idea is explored to explain an additional method of non-radiative depopulation of the excited state in the mid-IR that has not been properly recognized before: that of impurity multiphonon relaxation. Practical characterization of candidate selenide glasses is presented. Potential applications of mid-infrared fiber lasers are suggested.