Iron Fiber Laser
Abstract
Transition metal (TM) ions doped into chalcogenide crystals have been developed into commercially available mid-infrared (MIR) laser systems. However, these crystalline laser materials are not amenable to drawing into fiber. Here we report on the development of an optically active composite material consisting of Fe-doped ZnSe microparticles suspended in a chalcogenide glass matrix. This is a promising class of solid-state materials which can be drawn into a new generation of optical fibers for efficient and broadly tunable mid-infrared (MIR) lasers. A base chalcogenide glass (94.6 percent As2S3 5.4 percent As2Se3) was fabricated and shown to provide good refractive index matching in the 3-5 micro micro m region, necessary to reduce scattering by the ZnSe particles, However, powders of the base glass and ZnSe when mixed and heated to form a composite material showed signs of ZnSe being converted to ZnS. To address this issue, Fe2+:ZnSe particles were coated with a conformal shell of Al2O3, via Atomic Layer Deposition (ALD) to improve the stability of the Fe2+:ZnSe particles in the chalcogenide glass matrix melt environment. An ozone pretreatment of the ZnSe powders prior to ALD also improved particle stability, resulting in significant reduction in dissolution of coated powders. Moreover, an improvement in the drying protocol of the glass resulted in significantly lower impurity concentrations. Optical activity of the Fe2+ ions after fabrication of the composite material was confirmed by measuring broadband optical emission in the 3.52-5.20 micro m region when pumped at 2.9 micro m using an Er3+:YAG laser. Recent improvements in ALD coating and drying protocols resulted in a bulk optical composite with higher emission signal compared to previous composite material fabricated without these protocols, for the same loading levels. Preforms of the improved composites were drawn into fibers ~250 micro m in diameter.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 06, 2023
- Accession Number
- AD1230688
Entities
People
- Kathleen A. Richardson
- Kenneth L Schepler
- Martin C. Richardson
Organizations
- University of Central Florida