High-power fiber laser materials: influence of fabrication methods and codopants on optical properties

Structural origin of thermally induced refractive index changes in Yb3+/Al3+/P5+/F−‐co‐doped silica glass

“…It is imperative to study the origin of thermally induced RI and NA increase during the fiber‐drawing procedure. Admittedly, the Δn change may be attributed to residual elastic stresses from the drawing process, but the measured RI change is one order of magnitude larger than the stress‐induced RI change in the Yb 3+ /Al 3+ /P 5+ ‐co‐doped silica fibers with a P/Al ratio of 1 12‐14 . Some speculate that this behavior is associated with a slight change in the glass structure network during the fiber‐drawing process.…”

“…During the fiber‐drawing process, Δn was found to decrease by 1 × 10 −4 in the Yb 3+ /Al 3+ /F − ‐co‐doped and by 5 × 10 −4 in the Yb 3+ /Al 3+ ‐co‐doped silica fibers. By contrast, it was increased by 5 × 10 −4 in the Yb 3+ /Al 3+ /P 5+ ‐co‐doped silica fiber at a P/Al ratio of 1 11, 12 . It is imperative to study the origin of thermally induced RI and NA increase during the fiber‐drawing procedure.…”

“…By contrast, it was increased by 5 × 10 −4 in the Yb 3+ /Al 3+ /P 5+ -co-doped silica fiber at a P/Al ratio of 1. 11,12 It is imperative to study the origin of thermally induced RI and NA increase during the fiber-drawing procedure. Admittedly, the Δn change may be attributed to residual elastic stresses from the drawing process, but the measured RI change is one order of magnitude larger than the stress-induced RI change in the Yb 3+ /Al 3+ / P 5+ -co-doped silica fibers with a P/Al ratio of 1.…”

“…Admittedly, the Δn change may be attributed to residual elastic stresses from the drawing process, but the measured RI change is one order of magnitude larger than the stress-induced RI change in the Yb 3+ /Al 3+ / P 5+ -co-doped silica fibers with a P/Al ratio of 1. [12][13][14] Some speculate that this behavior is associated with a slight change in the glass structure network during the fiber-drawing process. However, an intimate and direct connection of the thermally induced physical behavior with the static and dynamic structural picture of the glasses, and a comparison between the core and the cladding glasses, are still lacking but are required.…”

Laser Cooling of a Yb Doped Silica Fiber by 18 Kelvin From Room Temperature

“…The high-purity fibers (Table I) were drawn from preforms fabricated with the modified chemical vapor deposition technique. Cation (Yb, Al) doping of the core was carried out by the gas-phase doping technique [32], using Yb(thd) 3 and AlCl 3 as precursors. Relative to previously successful laser cooling compositions doped with Al and F [10], the molar concentration of Yb 2 O 3 was increased by 25% for fiber A.…”